From 74400b55dc71c7a12c13c5334d75ce2d419d5b68 Mon Sep 17 00:00:00 2001
From: Li Haoyi <haoyi.sg@gmail.com>
Date: Sun, 2 Apr 2023 14:33:12 +0800
Subject: [PATCH 01/16] main tests pass

---
 .../src/mill/bsp/worker/MillBuildServer.scala |  2 +-
 build.sc                                      | 76 +++++++++----------
 main/api/src/mill/api/Ctx.scala               |  4 +-
 main/core/src/mill/define/Applicative.scala   |  4 +-
 main/core/src/mill/define/Router.scala        |  2 +-
 main/core/src/mill/define/Task.scala          | 50 ++++++------
 main/core/src/mill/eval/Evaluator.scala       | 14 ++--
 main/core/src/mill/eval/EvaluatorPaths.scala  |  4 +-
 .../mill/eval/EvaluatorPathsResolver.scala    |  4 +-
 .../mill/main/graphviz/GraphvizTools.scala    |  8 +-
 main/src/mill/main/MainModule.scala           | 16 ++--
 main/src/mill/main/Resolve.scala              |  2 +-
 main/src/mill/main/ResolveMetadata.scala      |  2 +-
 main/src/mill/main/ResolveSegments.scala      |  9 +--
 main/src/mill/main/ResolveTasks.scala         | 12 +--
 main/src/mill/main/RunScript.scala            |  2 +-
 main/src/mill/main/TokenReaders.scala         |  4 +-
 .../src/mill/define/ApplicativeTests.scala    |  2 +-
 main/test/src/mill/define/DiscoverTests.scala |  2 +-
 main/test/src/mill/define/GraphTests.scala    |  6 +-
 .../src/mill/define/MacroErrorTests.scala     | 30 ++++----
 main/test/src/mill/eval/EvaluationTests.scala | 10 +--
 .../src/mill/eval/JavaCompileJarTests.scala   |  4 +-
 main/test/src/mill/eval/TaskTests.scala       |  4 +-
 main/test/src/mill/main/MainTests.scala       |  6 +-
 main/test/src/mill/util/TestEvaluator.scala   |  2 +-
 main/test/src/mill/util/TestUtil.scala        |  2 +-
 .../src/mill/testkit/MillTestkit.scala        |  6 +-
 .../mill/scalajslib/HelloJSWorldTests.scala   |  2 +-
 .../src/mill/scalalib/HelloWorldTests.scala   | 18 ++---
 .../HelloNativeWorldTests.scala               |  2 +-
 31 files changed, 153 insertions(+), 158 deletions(-)

diff --git a/bsp/worker/src/mill/bsp/worker/MillBuildServer.scala b/bsp/worker/src/mill/bsp/worker/MillBuildServer.scala
index feb21f05edc..e63fe23fb1b 100644
--- a/bsp/worker/src/mill/bsp/worker/MillBuildServer.scala
+++ b/bsp/worker/src/mill/bsp/worker/MillBuildServer.scala
@@ -665,7 +665,7 @@ class MillBuildServer(
               logger = new MillBspLogger(client, cleanTask.hashCode, evaluator.baseLogger)
             )
             if (cleanResult.failing.keyCount > 0) (
-              msg + s" Target ${compileTargetName} could not be cleaned. See message from mill: \n" +
+              msg + s" CachedTarget ${compileTargetName} could not be cleaned. See message from mill: \n" +
                 (cleanResult.results(cleanTask) match {
                   case fail: Result.Failure[Any] => fail.msg + "\n"
                   case _ => "could not retrieve message"
diff --git a/build.sc b/build.sc
index 1e0e27a948f..fcaa023bf79 100644
--- a/build.sc
+++ b/build.sc
@@ -689,44 +689,44 @@ object contrib extends MillModule {
     override def testModuleDeps: Seq[JavaModule] = super.testModuleDeps ++ Seq(scalalib)
   }
 
-  object playlib extends MillModule {
-    override def moduleDeps = Seq(twirllib, playlib.api)
-    override def compileModuleDeps = Seq(scalalib)
-
-    override def testArgs = T {
-      val mapping = Map(
-        "MILL_CONTRIB_PLAYLIB_ROUTECOMPILER_WORKER_2_6" -> worker("2.6").assembly().path,
-        "MILL_CONTRIB_PLAYLIB_ROUTECOMPILER_WORKER_2_7" -> worker("2.7").assembly().path,
-        "MILL_CONTRIB_PLAYLIB_ROUTECOMPILER_WORKER_2_8" -> worker("2.8").assembly().path,
-        "TEST_PLAY_VERSION_2_6" -> Deps.Play_2_6.playVersion,
-        "TEST_PLAY_VERSION_2_7" -> Deps.Play_2_7.playVersion,
-        "TEST_PLAY_VERSION_2_8" -> Deps.Play_2_8.playVersion
-      )
-
-      scalalib.worker.testArgs() ++
-        scalalib.backgroundwrapper.testArgs() ++
-        (for ((k, v) <- mapping.to(Seq)) yield s"-D$k=$v")
-    }
-    override def testModuleDeps: Seq[JavaModule] = super.testModuleDeps ++ Seq(scalalib)
-
-    object api extends MillPublishModule
-
-    object worker extends Cross[WorkerModule](Deps.play.keys.toSeq: _*)
-    class WorkerModule(playBinary: String) extends MillInternalModule {
-      override def sources = T.sources {
-        // We want to avoid duplicating code as long as the Play APIs allow.
-        // But if newer Play versions introduce incompatibilities,
-        // just remove the shared source dir for that worker and implement directly.
-        Seq(PathRef(millSourcePath / os.up / "src-shared")) ++ super.sources()
-      }
-      override def scalaVersion = Deps.play(playBinary).scalaVersion
-      override def moduleDeps = Seq(playlib.api)
-      override def ivyDeps = Agg(
-        Deps.osLib,
-        Deps.play(playBinary).routesCompiler
-      )
-    }
-  }
+//  object playlib extends MillModule {
+//    override def moduleDeps = Seq(twirllib, playlib.api)
+//    override def compileModuleDeps = Seq(scalalib)
+//
+//    override def testArgs = T {
+//      val mapping = Map(
+//        "MILL_CONTRIB_PLAYLIB_ROUTECOMPILER_WORKER_2_6" -> worker("2.6").assembly().path,
+//        "MILL_CONTRIB_PLAYLIB_ROUTECOMPILER_WORKER_2_7" -> worker("2.7").assembly().path,
+//        "MILL_CONTRIB_PLAYLIB_ROUTECOMPILER_WORKER_2_8" -> worker("2.8").assembly().path,
+//        "TEST_PLAY_VERSION_2_6" -> Deps.Play_2_6.playVersion,
+//        "TEST_PLAY_VERSION_2_7" -> Deps.Play_2_7.playVersion,
+//        "TEST_PLAY_VERSION_2_8" -> Deps.Play_2_8.playVersion
+//      )
+//
+//      scalalib.worker.testArgs() ++
+//        scalalib.backgroundwrapper.testArgs() ++
+//        (for ((k, v) <- mapping.to(Seq)) yield s"-D$k=$v")
+//    }
+//    override def testModuleDeps: Seq[JavaModule] = super.testModuleDeps ++ Seq(scalalib)
+//
+//    object api extends MillPublishModule
+//
+//    object worker extends Cross[WorkerModule](Deps.play.keys.toSeq: _*)
+//    class WorkerModule(playBinary: String) extends MillInternalModule {
+//      override def sources = T.sources {
+//        // We want to avoid duplicating code as long as the Play APIs allow.
+//        // But if newer Play versions introduce incompatibilities,
+//        // just remove the shared source dir for that worker and implement directly.
+//        Seq(PathRef(millSourcePath / os.up / "src-shared")) ++ super.sources()
+//      }
+//      override def scalaVersion = Deps.play(playBinary).scalaVersion
+//      override def moduleDeps = Seq(playlib.api)
+//      override def ivyDeps = Agg(
+//        Deps.osLib,
+//        Deps.play(playBinary).routesCompiler
+//      )
+//    }
+//  }
 
   object scalapblib extends MillModule {
     override def compileModuleDeps = Seq(scalalib)
diff --git a/main/api/src/mill/api/Ctx.scala b/main/api/src/mill/api/Ctx.scala
index b78e017e265..d78cd5f76f9 100644
--- a/main/api/src/mill/api/Ctx.scala
+++ b/main/api/src/mill/api/Ctx.scala
@@ -5,10 +5,10 @@ import scala.language.implicitConversions
 import os.Path
 
 /**
- * Provides access to various resources in the context of a currently execution Target.
+ * Provides access to various resources in the context of a currently execution CachedTarget.
  */
 object Ctx {
-  @compileTimeOnly("Target.ctx() / T.ctx() / T.* APIs can only be used with a T{...} block")
+  @compileTimeOnly("CachedTarget.ctx() / T.ctx() / T.* APIs can only be used with a T{...} block")
   @ImplicitStub
   implicit def taskCtx: Ctx = ???
 
diff --git a/main/core/src/mill/define/Applicative.scala b/main/core/src/mill/define/Applicative.scala
index ff212a7a30e..6c50b1663c3 100644
--- a/main/core/src/mill/define/Applicative.scala
+++ b/main/core/src/mill/define/Applicative.scala
@@ -18,7 +18,7 @@ object Applicative {
     def apply[T](t: M[T]): T
   }
   object ApplyHandler {
-    @compileTimeOnly("Target#apply() can only be used with a T{...} block")
+    @compileTimeOnly("CachedTarget#apply() can only be used with a T{...} block")
     implicit def defaultApplyHandler[M[+_]]: ApplyHandler[M] = ???
   }
   trait Applyable[M[+_], +T] {
@@ -64,7 +64,7 @@ object Applicative {
           val banned0 = banned.next()
           c.abort(
             banned0.pos,
-            "Target#apply() call cannot use `" + banned0.symbol + "` defined within the T{...} block"
+            "CachedTarget#apply() call cannot use `" + banned0.symbol + "` defined within the T{...} block"
           )
         }
         val tempName = c.freshName(TermName("tmp"))
diff --git a/main/core/src/mill/define/Router.scala b/main/core/src/mill/define/Router.scala
index fff732ea88d..c0f2f7d7349 100644
--- a/main/core/src/mill/define/Router.scala
+++ b/main/core/src/mill/define/Router.scala
@@ -62,7 +62,7 @@ class Router(val ctx: blackbox.Context) extends mainargs.Macros(ctx) {
           (weakTypeOf[mill.define.Sources], 0, "`T.sources`"),
           (weakTypeOf[mill.define.Input[_]], 0, "`T.input`"),
           (weakTypeOf[mill.define.Persistent[_]], 0, "`T.persistent`"),
-          (weakTypeOf[mill.define.Target[_]], 0, "`T{...}`"),
+          (weakTypeOf[mill.define.CachedTarget[_]], 0, "`T{...}`"),
           (weakTypeOf[mill.define.Command[_]], 1, "`T.command`")
         )
 
diff --git a/main/core/src/mill/define/Task.scala b/main/core/src/mill/define/Task.scala
index d2c4eaeec62..0b40bf92894 100644
--- a/main/core/src/mill/define/Task.scala
+++ b/main/core/src/mill/define/Task.scala
@@ -12,12 +12,12 @@ import scala.reflect.macros.blackbox.Context
  * single output of type [[T]].
  *
  * Generally not instantiated manually, but instead constructed via the
- * [[Target.apply]] & similar macros.
+ * [[CachedTarget.apply]] & similar macros.
  */
 abstract class Task[+T] extends Task.Ops[T] with Applyable[Task, T] {
 
   /**
-   * What other Targets does this Target depend on?
+   * What other Targets does this CachedTarget depend on?
    */
   val inputs: Seq[Task[_]]
 
@@ -34,25 +34,25 @@ abstract class Task[+T] extends Task.Ops[T] with Applyable[Task, T] {
 
   def flushDest: Boolean = true
 
-  def asTarget: Option[Target[T]] = None
+  def asTarget: Option[CachedTarget[T]] = None
   def asCommand: Option[Command[T]] = None
   def asWorker: Option[Worker[T]] = None
   def self: Task[T] = this
 }
 
-trait NamedTask[+T] extends Task[T] {
+trait Target[+T] extends Task[T] {
   def ctx: mill.define.Ctx
   def label: String = ctx.segment match {
     case Segment.Label(v) => v
     case Segment.Cross(_) => throw new IllegalArgumentException(
-        "NamedTask only support a ctx with a Label segment, but found a Cross."
+        "Target only support a ctx with a Label segment, but found a Cross."
       )
   }
   override def toString = ctx.segments.render
   def isPrivate: Option[Boolean] = None
 }
-trait Target[+T] extends NamedTask[T] {
-  override def asTarget: Option[Target[T]] = Some(this)
+trait CachedTarget[+T] extends Target[T] {
+  override def asTarget: Option[CachedTarget[T]] = Some(this)
   def readWrite: RW[_]
 }
 
@@ -73,16 +73,16 @@ object Target extends Applicative.Applyer[Task, Task, Result, mill.api.Ctx] {
   def targetImpl[T: c.WeakTypeTag](c: Context)(t: c.Expr[T])(
       rw: c.Expr[RW[T]],
       ctx: c.Expr[mill.define.Ctx]
-  ): c.Expr[Target[T]] = {
+  ): c.Expr[CachedTarget[T]] = {
     import c.universe._
 
     val taskIsPrivate = isPrivateTargetOption(c)
 
     val lhs = Applicative.impl0[Task, T, mill.api.Ctx](c)(reify(Result.Success(t.splice)).tree)
 
-    mill.moduledefs.Cacher.impl0[TargetImpl[T]](c)(
+    mill.moduledefs.Cacher.impl0[CachedTarget[T]](c)(
       reify(
-        new TargetImpl[T](
+        new CachedTargetImpl[T](
           lhs.splice,
           ctx.splice,
           rw.splice,
@@ -104,14 +104,14 @@ object Target extends Applicative.Applyer[Task, Task, Result, mill.api.Ctx] {
   def targetResultImpl[T: c.WeakTypeTag](c: Context)(t: c.Expr[Result[T]])(
       rw: c.Expr[RW[T]],
       ctx: c.Expr[mill.define.Ctx]
-  ): c.Expr[Target[T]] = {
+  ): c.Expr[CachedTarget[T]] = {
     import c.universe._
 
     val taskIsPrivate = isPrivateTargetOption(c)
 
-    mill.moduledefs.Cacher.impl0[Target[T]](c)(
+    mill.moduledefs.Cacher.impl0[CachedTarget[T]](c)(
       reify(
-        new TargetImpl[T](
+        new CachedTargetImpl[T](
           Applicative.impl0[Task, T, mill.api.Ctx](c)(t.tree).splice,
           ctx.splice,
           rw.splice,
@@ -127,14 +127,14 @@ object Target extends Applicative.Applyer[Task, Task, Result, mill.api.Ctx] {
   def targetTaskImpl[T: c.WeakTypeTag](c: Context)(t: c.Expr[Task[T]])(
       rw: c.Expr[RW[T]],
       ctx: c.Expr[mill.define.Ctx]
-  ): c.Expr[Target[T]] = {
+  ): c.Expr[CachedTarget[T]] = {
     import c.universe._
 
     val taskIsPrivate = isPrivateTargetOption(c)
 
-    mill.moduledefs.Cacher.impl0[Target[T]](c)(
+    mill.moduledefs.Cacher.impl0[CachedTarget[T]](c)(
       reify(
-        new TargetImpl[T](
+        new CachedTargetImpl[T](
           t.splice,
           ctx.splice,
           rw.splice,
@@ -375,23 +375,23 @@ object Target extends Applicative.Applyer[Task, Task, Result, mill.api.Ctx] {
   }
 }
 
-abstract class NamedTaskImpl[+T](
+abstract class TargetImpl[+T](
     ctx0: mill.define.Ctx,
     t: Task[T],
     override val isPrivate: Option[Boolean]
-) extends NamedTask[T] {
+) extends Target[T] {
   def evaluate(args: mill.api.Ctx) = args[T](0)
   val ctx = ctx0.withSegments(segments = ctx0.segments ++ Seq(ctx0.segment))
   val inputs = Seq(t)
 }
 
-class TargetImpl[+T](
+class CachedTargetImpl[+T](
     t: Task[T],
     ctx0: mill.define.Ctx,
     override val readWrite: RW[_],
     isPrivate: Option[Boolean]
-) extends NamedTaskImpl[T](ctx0, t, isPrivate)
-    with Target[T] {}
+) extends TargetImpl[T](ctx0, t, isPrivate)
+    with CachedTarget[T] {}
 
 class Command[+T](
     t: Task[T],
@@ -399,12 +399,12 @@ class Command[+T](
     val writer: W[_],
     val cls: Class[_],
     isPrivate: Option[Boolean]
-) extends NamedTaskImpl[T](ctx0, t, isPrivate) {
+) extends TargetImpl[T](ctx0, t, isPrivate) {
   override def asCommand = Some(this)
 }
 
 class Worker[+T](t: Task[T], ctx0: mill.define.Ctx, isPrivate: Option[Boolean])
-    extends NamedTaskImpl[T](ctx0, t, isPrivate) {
+    extends TargetImpl[T](ctx0, t, isPrivate) {
   override def flushDest = false
   override def asWorker = Some(this)
 }
@@ -414,7 +414,7 @@ class Persistent[+T](
     ctx0: mill.define.Ctx,
     readWrite: RW[_],
     isPrivate: Option[Boolean]
-) extends TargetImpl[T](t, ctx0, readWrite, isPrivate) {
+) extends CachedTargetImpl[T](t, ctx0, readWrite, isPrivate) {
 
   override def flushDest = false
 }
@@ -424,7 +424,7 @@ class Input[T](
     ctx0: mill.define.Ctx,
     val writer: upickle.default.Writer[_],
     isPrivate: Option[Boolean]
-) extends NamedTaskImpl[T](ctx0, t, isPrivate) {
+) extends TargetImpl[T](ctx0, t, isPrivate) {
   override def sideHash = util.Random.nextInt()
 }
 
diff --git a/main/core/src/mill/eval/Evaluator.scala b/main/core/src/mill/eval/Evaluator.scala
index bfc0404321a..f86c50d269e 100644
--- a/main/core/src/mill/eval/Evaluator.scala
+++ b/main/core/src/mill/eval/Evaluator.scala
@@ -23,15 +23,15 @@ import scala.jdk.CollectionConverters._
 import scala.reflect.ClassTag
 import scala.util.control.NonFatal
 
-case class Labelled[T](task: NamedTask[T], segments: Segments) {
+case class Labelled[T](task: Target[T], segments: Segments) {
   def format: Option[default.ReadWriter[T]] = task match {
-    case t: Target[T] => Some(t.readWrite.asInstanceOf[upickle.default.ReadWriter[T]])
+    case t: CachedTarget[T] => Some(t.readWrite.asInstanceOf[upickle.default.ReadWriter[T]])
     case _ => None
   }
   def writer: Option[default.Writer[T]] = task match {
     case t: mill.define.Command[T] => Some(t.writer.asInstanceOf[upickle.default.Writer[T]])
     case t: mill.define.Input[T] => Some(t.writer.asInstanceOf[upickle.default.Writer[T]])
-    case t: Target[T] => Some(t.readWrite.asInstanceOf[upickle.default.ReadWriter[T]])
+    case t: CachedTarget[T] => Some(t.readWrite.asInstanceOf[upickle.default.ReadWriter[T]])
     case _ => None
   }
 }
@@ -329,7 +329,7 @@ class Evaluator private (_home: os.Path,
     val scriptsHash = {
       val scripts = new Loose.Agg.Mutable[os.Path]()
       group.iterator.flatMap(t => Iterator(t) ++ t.inputs).foreach {
-        case namedTask: NamedTask[_] => scripts.append(os.Path(namedTask.ctx.fileName))
+        case namedTask: Target[_] => scripts.append(os.Path(namedTask.ctx.fileName))
         case _ =>
       }
 
@@ -821,10 +821,10 @@ object Evaluator {
     val seen = collection.mutable.Set.empty[Segments]
     val overridden = collection.mutable.Set.empty[Task[_]]
     topoSorted.values.reverse.iterator.foreach {
-      case x: NamedTask[_] if x.isPrivate == Some(true) =>
+      case x: Target[_] if x.isPrivate == Some(true) =>
         // we always need to store them in the super-path
         overridden.add(x)
-      case x: NamedTask[_] =>
+      case x: Target[_] =>
         if (!seen.contains(x.ctx.segments)) seen.add(x.ctx.segments)
         else overridden.add(x)
       case _ => // donothing
@@ -832,7 +832,7 @@ object Evaluator {
 
     val sortedGroups = Graph.groupAroundImportantTargets(topoSorted) {
       // important: all named tasks and those explicitly requested
-      case t: NamedTask[Any] =>
+      case t: Target[Any] =>
         val segments = t.ctx.segments
         Right(
           Labelled(
diff --git a/main/core/src/mill/eval/EvaluatorPaths.scala b/main/core/src/mill/eval/EvaluatorPaths.scala
index b1516a10453..d8392485815 100644
--- a/main/core/src/mill/eval/EvaluatorPaths.scala
+++ b/main/core/src/mill/eval/EvaluatorPaths.scala
@@ -1,7 +1,7 @@
 package mill.eval
 
 import mill.api.internal
-import mill.define.{NamedTask, Segment, Segments}
+import mill.define.{Target, Segment, Segments}
 
 case class EvaluatorPaths private (dest: os.Path, meta: os.Path, log: os.Path) {
   private def copy(dest: os.Path = dest, meta: os.Path = meta, log: os.Path = log): EvaluatorPaths =
@@ -37,6 +37,6 @@ object EvaluatorPaths {
   }
   def resolveDestPaths(
       workspacePath: os.Path,
-      task: NamedTask[_]
+      task: Target[_]
   ): EvaluatorPaths = resolveDestPaths(workspacePath, task.ctx.segments, task.ctx.foreign)
 }
diff --git a/main/core/src/mill/eval/EvaluatorPathsResolver.scala b/main/core/src/mill/eval/EvaluatorPathsResolver.scala
index f7d0ad31907..1843c311a03 100644
--- a/main/core/src/mill/eval/EvaluatorPathsResolver.scala
+++ b/main/core/src/mill/eval/EvaluatorPathsResolver.scala
@@ -1,9 +1,9 @@
 package mill.eval
 
-import mill.define.{NamedTask, Segments}
+import mill.define.{Target, Segments}
 
 trait EvaluatorPathsResolver {
-  def resolveDest(task: NamedTask[_]): EvaluatorPaths =
+  def resolveDest(task: Target[_]): EvaluatorPaths =
     resolveDest(task.ctx.segments, task.ctx.foreign)
   def resolveDest(segments: Segments, foreignSegments: Option[Segments] = None): EvaluatorPaths
 }
diff --git a/main/graphviz/src/mill/main/graphviz/GraphvizTools.scala b/main/graphviz/src/mill/main/graphviz/GraphvizTools.scala
index 007b0c6bc48..f830f3d8f66 100644
--- a/main/graphviz/src/mill/main/graphviz/GraphvizTools.scala
+++ b/main/graphviz/src/mill/main/graphviz/GraphvizTools.scala
@@ -1,14 +1,14 @@
 package mill.main.graphviz
 import guru.nidi.graphviz.attribute.Style
-import mill.define.{Graph, NamedTask}
+import mill.define.{Graph, Target}
 import org.jgrapht.graph.{DefaultEdge, SimpleDirectedGraph}
 object GraphvizTools {
-  def apply(targets: Seq[NamedTask[Any]], rs: Seq[NamedTask[Any]], dest: os.Path) = {
+  def apply(targets: Seq[Target[Any]], rs: Seq[Target[Any]], dest: os.Path) = {
     val transitive = Graph.transitiveTargets(rs.distinct)
     val topoSorted = Graph.topoSorted(transitive)
     val goalSet = rs.toSet
     val sortedGroups = Graph.groupAroundImportantTargets(topoSorted) {
-      case x: NamedTask[Any] if goalSet.contains(x) => x
+      case x: Target[Any] if goalSet.contains(x) => x
     }
     import guru.nidi.graphviz.engine.{Format, Graphviz}
     import guru.nidi.graphviz.model.Factory._
@@ -19,7 +19,7 @@ object GraphvizTools {
           k,
           for {
             v <- vs.items
-            dest <- v.inputs.collect { case v: NamedTask[Any] => v }
+            dest <- v.inputs.collect { case v: Target[Any] => v }
             if goalSet.contains(dest)
           } yield dest
         )
diff --git a/main/src/mill/main/MainModule.scala b/main/src/mill/main/MainModule.scala
index cd1c0712797..2e441dc15e0 100644
--- a/main/src/mill/main/MainModule.scala
+++ b/main/src/mill/main/MainModule.scala
@@ -5,7 +5,7 @@ import mainargs.TokensReader
 import java.util.concurrent.LinkedBlockingQueue
 import mill.{BuildInfo, T}
 import mill.api.{Ctx, PathRef, Result, internal}
-import mill.define.{Command, NamedTask, Segments, SelectMode, Target, Task}
+import mill.define.{Command, Target, Segments, SelectMode, CachedTarget, Task}
 import mill.eval.{Evaluator, EvaluatorPaths}
 import mill.util.{PrintLogger, Watched}
 import pprint.{Renderer, Tree, Truncated}
@@ -20,7 +20,7 @@ object MainModule {
       evaluator: Evaluator,
       targets: Seq[String],
       selectMode: SelectMode
-  )(f: List[NamedTask[Any]] => T): Result[T] = {
+  )(f: List[Target[Any]] => T): Result[T] = {
     RunScript.resolveTasks(mill.main.ResolveTasks, evaluator, targets, selectMode) match {
       case Left(err) => Result.Failure(err)
       case Right(tasks) => Result.Success(f(tasks))
@@ -155,7 +155,7 @@ trait MainModule extends mill.Module {
             Result.Failure(s"No path found between $src and $dest")
           case Some(list) =>
             val labels = list
-              .collect { case n: NamedTask[_] => n.ctx.segments.render }
+              .collect { case n: Target[_] => n.ctx.segments.render }
 
             labels.foreach(mill.T.log.outputStream.println(_))
 
@@ -174,13 +174,13 @@ trait MainModule extends mill.Module {
         resolveParents
       )
     }
-    def pprintTask(t: NamedTask[_], evaluator: Evaluator): Tree.Lazy = {
+    def pprintTask(t: Target[_], evaluator: Evaluator): Tree.Lazy = {
       val seen = mutable.Set.empty[Task[_]]
 
       def rec(t: Task[_]): Seq[Segments] = {
         if (seen(t)) Nil // do nothing
         else t match {
-          case t: Target[_] if evaluator.rootModule.millInternal.targets.contains(t) =>
+          case t: CachedTarget[_] if evaluator.rootModule.millInternal.targets.contains(t) =>
             Seq(t.ctx.segments)
           case _ =>
             seen.add(t)
@@ -399,11 +399,11 @@ trait MainModule extends mill.Module {
       targets: Seq[String],
       ctx: Ctx,
       vizWorker: VizWorker,
-      planTasks: Option[List[NamedTask[_]]] = None
+      planTasks: Option[List[Target[_]]] = None
   ): Result[Seq[PathRef]] = {
     def callVisualizeModule(
-        rs: List[NamedTask[Any]],
-        allRs: List[NamedTask[Any]]
+        rs: List[Target[Any]],
+        allRs: List[Target[Any]]
     ): Result[Seq[PathRef]] = {
       val (in, out) = vizWorker
       in.put((rs, allRs, ctx.dest))
diff --git a/main/src/mill/main/Resolve.scala b/main/src/mill/main/Resolve.scala
index 940f0eba62a..5cbe181b2c6 100644
--- a/main/src/mill/main/Resolve.scala
+++ b/main/src/mill/main/Resolve.scala
@@ -244,7 +244,7 @@ abstract class Resolve[R: ClassTag] {
               }
             ).map(
               _.distinctBy {
-                case t: NamedTask[_] => t.ctx.segments
+                case t: Target[_] => t.ctx.segments
                 case t => t
               }
             )
diff --git a/main/src/mill/main/ResolveMetadata.scala b/main/src/mill/main/ResolveMetadata.scala
index 43fa1fded21..b72521844f2 100644
--- a/main/src/mill/main/ResolveMetadata.scala
+++ b/main/src/mill/main/ResolveMetadata.scala
@@ -8,7 +8,7 @@ object ResolveMetadata extends Resolve[String] {
     val targets =
       obj
         .millInternal
-        .reflectAll[NamedTask[_]]
+        .reflectAll[Target[_]]
         .map(_.toString)
     val commands =
       for {
diff --git a/main/src/mill/main/ResolveSegments.scala b/main/src/mill/main/ResolveSegments.scala
index 7418ee67576..0a26cc03711 100644
--- a/main/src/mill/main/ResolveSegments.scala
+++ b/main/src/mill/main/ResolveSegments.scala
@@ -43,25 +43,20 @@ object ResolveSegments extends Resolve[Segments] {
       discover: Discover[_],
       rest: Seq[String]
   ): Either[String, Seq[Segments]] = {
+
     val target =
       obj
         .millInternal
         .reflectSingle[Target[_]](last)
         .map(t => Right(t.ctx.segments))
 
-    val command =
-      Resolve
-        .invokeCommand(obj, last, discover.asInstanceOf[Discover[Module]], rest)
-        .headOption
-        .map(_.map(_.ctx.segments))
-
     val module =
       obj.millInternal
         .reflectNestedObjects[Module]
         .find(_.millOuterCtx.segment == Segment.Label(last))
         .map(m => Right(m.millModuleSegments))
 
-    command orElse target orElse module match {
+    target orElse module match {
       case None =>
         Resolve.errorMsgLabel(
           singleModuleMeta(obj, discover, obj.millModuleSegments.value.isEmpty),
diff --git a/main/src/mill/main/ResolveTasks.scala b/main/src/mill/main/ResolveTasks.scala
index 28b4a2e88ca..6b4d3e1896a 100644
--- a/main/src/mill/main/ResolveTasks.scala
+++ b/main/src/mill/main/ResolveTasks.scala
@@ -3,14 +3,14 @@ package mill.main
 import mill.define._
 import mill.main.ResolveMetadata.singleModuleMeta
 
-object ResolveTasks extends Resolve[NamedTask[Any]] {
+object ResolveTasks extends Resolve[Target[Any]] {
 
   def endResolveCross(
       obj: Module,
       last: List[String],
       discover: Discover[_],
       rest: Seq[String]
-  ): Either[String, Seq[NamedTask[Any]]] = {
+  ): Either[String, Seq[Target[Any]]] = {
     obj match {
       case _: Cross[Module] =>
         Resolve.runDefault(obj, Segment.Cross(last), discover, rest).flatten.headOption match {
@@ -34,20 +34,20 @@ object ResolveTasks extends Resolve[NamedTask[Any]] {
       last: String,
       discover: Discover[_],
       rest: Seq[String]
-  ): Either[String, Seq[NamedTask[Any]]] = last match {
+  ): Either[String, Seq[Target[Any]]] = last match {
     case "__" =>
       Right(
         obj.millInternal.modules
           .filter(_ != obj)
-          .flatMap(m => m.millInternal.reflectAll[NamedTask[_]])
+          .flatMap(m => m.millInternal.reflectAll[Target[_]])
       )
-    case "_" => Right(obj.millInternal.reflectAll[NamedTask[_]])
+    case "_" => Right(obj.millInternal.reflectAll[Target[_]])
 
     case _ =>
       val target =
         obj
           .millInternal
-          .reflectSingle[NamedTask[_]](last)
+          .reflectSingle[Target[_]](last)
           .map(Right(_))
 
       val command = Resolve.invokeCommand(
diff --git a/main/src/mill/main/RunScript.scala b/main/src/mill/main/RunScript.scala
index 457591c1664..d366d12203a 100644
--- a/main/src/mill/main/RunScript.scala
+++ b/main/src/mill/main/RunScript.scala
@@ -181,7 +181,7 @@ object RunScript {
       case 0 =>
         val nameAndJson = for (t <- targets.toSeq) yield {
           t match {
-            case t: mill.define.NamedTask[_] =>
+            case t: mill.define.Target[_] =>
               val jsonFile = EvaluatorPaths.resolveDestPaths(evaluator.outPath, t).meta
               val metadata = upickle.default.read[Evaluator.Cached](ujson.read(jsonFile.toIO))
               Some(t.toString, metadata.value)
diff --git a/main/src/mill/main/TokenReaders.scala b/main/src/mill/main/TokenReaders.scala
index 42c4eff001d..1ef796f183d 100644
--- a/main/src/mill/main/TokenReaders.scala
+++ b/main/src/mill/main/TokenReaders.scala
@@ -4,7 +4,7 @@ import mainargs.TokensReader
 import mill.eval.Evaluator
 import mill.define.{SelectMode, Target, Task}
 
-case class Tasks[T](value: Seq[mill.define.NamedTask[T]])
+case class Tasks[T](value: Seq[mill.define.Target[T]])
 
 object Tasks {
   class TokenReader[T]()
@@ -16,7 +16,7 @@ object Tasks {
             Evaluator.currentEvaluator.get,
             s,
             SelectMode.Single
-          ).map(x => Tasks(x.asInstanceOf[Seq[mill.define.NamedTask[T]]])),
+          ).map(x => Tasks(x.asInstanceOf[Seq[mill.define.Target[T]]])),
         alwaysRepeatable = false,
         allowEmpty = false
       )
diff --git a/main/test/src/mill/define/ApplicativeTests.scala b/main/test/src/mill/define/ApplicativeTests.scala
index 1eede908af2..46e03036f06 100644
--- a/main/test/src/mill/define/ApplicativeTests.scala
+++ b/main/test/src/mill/define/ApplicativeTests.scala
@@ -27,7 +27,7 @@ object ApplicativeTests extends TestSuite {
       value
     }
   }
-  @compileTimeOnly("Target.ctx() can only be used with a T{...} block")
+  @compileTimeOnly("CachedTarget.ctx() can only be used with a T{...} block")
   @ImplicitStub
   implicit def taskCtx: String = ???
 
diff --git a/main/test/src/mill/define/DiscoverTests.scala b/main/test/src/mill/define/DiscoverTests.scala
index a08281c2db7..128d0dffd26 100644
--- a/main/test/src/mill/define/DiscoverTests.scala
+++ b/main/test/src/mill/define/DiscoverTests.scala
@@ -7,7 +7,7 @@ object DiscoverTests extends TestSuite {
   val testGraphs = new TestGraphs
   val tests = Tests {
     def check[T <: Module](m: T)(targets: (T => Target[_])*) = {
-      val discovered = m.millInternal.targets
+      val discovered = m.millInternal.targets.filter(_.asCommand.isEmpty)
       val expected = targets.map(_(m)).toSet
       assert(discovered == expected)
     }
diff --git a/main/test/src/mill/define/GraphTests.scala b/main/test/src/mill/define/GraphTests.scala
index 449fffefd55..f4e931fbe83 100644
--- a/main/test/src/mill/define/GraphTests.scala
+++ b/main/test/src/mill/define/GraphTests.scala
@@ -79,7 +79,7 @@ object GraphTests extends TestSuite {
 
         val important = important0.map(_(base))
         val grouped = Graph.groupAroundImportantTargets(topoSorted) {
-          case t: Target[_] if important.contains(t) => t
+          case t: CachedTarget[_] if important.contains(t) => t: Target[_]
         }
         val flattened = Agg.from(grouped.values().flatMap(_.items))
 
@@ -88,7 +88,7 @@ object GraphTests extends TestSuite {
           val grouping = grouped.lookupKey(terminal)
           assert(
             grouping.size == expectedSize,
-            grouping.flatMap(_.asTarget: Option[Target[_]]).filter(important.contains) == Agg(
+            grouping.flatMap(_.asTarget: Option[CachedTarget[_]]).filter(important.contains) == Agg(
               terminal
             )
           )
@@ -168,7 +168,7 @@ object GraphTests extends TestSuite {
           Graph.transitiveTargets(Agg.from(goals))
         )
         val grouped = Graph.groupAroundImportantTargets(topoSorted) {
-          case t: NamedTask[Any] => t
+          case t: Target[Any] => t
           case t if goals.contains(t) => t
         }
         grouped.keyCount
diff --git a/main/test/src/mill/define/MacroErrorTests.scala b/main/test/src/mill/define/MacroErrorTests.scala
index e620ef2823f..cdda22b6881 100644
--- a/main/test/src/mill/define/MacroErrorTests.scala
+++ b/main/test/src/mill/define/MacroErrorTests.scala
@@ -28,18 +28,18 @@ object MacroErrorTests extends TestSuite {
           e.pos.contains("def w = ")
         )
       }
-      "target" - {
-        val e = compileError("""
-          object foo extends mill.util.TestUtil.BaseModule{
-            def x() = T{1}
-          }
-          mill.define.Discover[foo.type]
-        """)
-        assert(
-          e.msg.contains("`T{...}` definitions must have 0 parameter lists"),
-          e.pos.contains("def x() = ")
-        )
-      }
+//      "target" - {
+//        val e = compileError("""
+//          object foo extends mill.util.TestUtil.BaseModule{
+//            def x() = T{1}
+//          }
+//          mill.define.Discover[foo.type]
+//        """)
+//        assert(
+//          e.msg.contains("`T{...}` definitions must have 0 parameter lists"),
+//          e.pos.contains("def x() = ")
+//        )
+//      }
       "input" - {
         val e = compileError("""
           object foo extends mill.util.TestUtil.BaseModule{
@@ -79,7 +79,7 @@ object MacroErrorTests extends TestSuite {
     }
     "badTmacro" - {
       // Make sure we can reference values from outside the T{...} block as part
-      // of our `Target#apply()` calls, but we cannot reference any values that
+      // of our `CachedTarget#apply()` calls, but we cannot reference any values that
       // come from inside the T{...} block
       "pos" - {
         val e = compileError("""
@@ -99,7 +99,7 @@ object MacroErrorTests extends TestSuite {
       "neg" - {
 
         val expectedMsg =
-          "Target#apply() call cannot use `value n` defined within the T{...} block"
+          "CachedTarget#apply() call cannot use `value n` defined within the T{...} block"
         val err = compileError("""new Module{
           def a = T{ 1 }
           val arr = Array(a)
@@ -115,7 +115,7 @@ object MacroErrorTests extends TestSuite {
       "neg2" - {
 
         val expectedMsg =
-          "Target#apply() call cannot use `value x` defined within the T{...} block"
+          "CachedTarget#apply() call cannot use `value x` defined within the T{...} block"
         val err = compileError("""new Module{
           def a = T{ 1 }
           val arr = Array(a)
diff --git a/main/test/src/mill/eval/EvaluationTests.scala b/main/test/src/mill/eval/EvaluationTests.scala
index 36098a27fd8..36600fc90f5 100644
--- a/main/test/src/mill/eval/EvaluationTests.scala
+++ b/main/test/src/mill/eval/EvaluationTests.scala
@@ -1,7 +1,7 @@
 package mill.eval
 
 import mill.util.TestUtil.{Test, test}
-import mill.define.{Discover, Graph, Target, Task}
+import mill.define.{Discover, Graph, CachedTarget, Task}
 import mill.{Module, T}
 import mill.util.{DummyLogger, TestEvaluator, TestGraphs, TestUtil}
 import mill.api.Strict.Agg
@@ -181,14 +181,14 @@ class EvaluationTests(threadCount: Option[Int]) extends TestSuite {
         import separateGroups._
         val checker = new Checker(separateGroups)
         val evaled1 = checker.evaluator.evaluate(Agg(right, left))
-        val filtered1 = evaled1.evaluated.filter(_.isInstanceOf[Target[_]])
+        val filtered1 = evaled1.evaluated.filter(_.isInstanceOf[CachedTarget[_]])
         assert(filtered1.toSeq.sortBy(_.toString) == Seq(change, left, right).sortBy(_.toString))
         val evaled2 = checker.evaluator.evaluate(Agg(right, left))
-        val filtered2 = evaled2.evaluated.filter(_.isInstanceOf[Target[_]])
+        val filtered2 = evaled2.evaluated.filter(_.isInstanceOf[CachedTarget[_]])
         assert(filtered2 == Agg())
         change.counter += 1
         val evaled3 = checker.evaluator.evaluate(Agg(right, left))
-        val filtered3 = evaled3.evaluated.filter(_.isInstanceOf[Target[_]])
+        val filtered3 = evaled3.evaluated.filter(_.isInstanceOf[CachedTarget[_]])
         assert(filtered3 == Agg(change, right))
 
       }
@@ -337,7 +337,7 @@ class EvaluationTests(threadCount: Option[Int]) extends TestSuite {
         // But if `up` changes, the entire block of downstream tasks needs to
         // recompute together, including `middle` which doesn't depend on `up`,
         // because tasks have no cached value that can be used. `right`, which
-        // is a cached Target, does not recompute
+        // is a cached CachedTarget, does not recompute
         up.inputs(0).asInstanceOf[Test].counter += 1
         check(down, expValue = 10102, expEvaled = Agg(up, down), extraEvaled = 4)
         assert(leftCount == 2, middleCount == 2, rightCount == 1)
diff --git a/main/test/src/mill/eval/JavaCompileJarTests.scala b/main/test/src/mill/eval/JavaCompileJarTests.scala
index 9839929413a..a617f5d36c8 100644
--- a/main/test/src/mill/eval/JavaCompileJarTests.scala
+++ b/main/test/src/mill/eval/JavaCompileJarTests.scala
@@ -1,6 +1,6 @@
 package mill.eval
 
-import mill.define.{Discover, Input, Target, Task}
+import mill.define.{Discover, Input, CachedTarget, Task}
 import mill.modules.Jvm
 import mill.api.Ctx.Dest
 import mill.{Module, T}
@@ -87,7 +87,7 @@ object JavaCompileJarTests extends TestSuite {
       // exactly the same so no re-jarring.
       append(sourceRootPath / "Foo.java", " ")
       // Note that `sourceRoot` and `resourceRoot` never turn up in the `expected`
-      // list, because they are `Source`s not `Target`s
+      // list, because they are `Source`s not `CachedTarget`s
       check(targets = Agg(jar), expected = Agg( /*sourceRoot, */ allSources, classFiles))
 
       // Appending a new class changes the classfiles, which forces us to
diff --git a/main/test/src/mill/eval/TaskTests.scala b/main/test/src/mill/eval/TaskTests.scala
index 4b687d07cd6..bc7f0fbfe31 100644
--- a/main/test/src/mill/eval/TaskTests.scala
+++ b/main/test/src/mill/eval/TaskTests.scala
@@ -97,14 +97,14 @@ trait TaskTests extends TestSuite {
 
     "inputs" - withEnv { (build, check) =>
       // Inputs always re-evaluate, including forcing downstream cached Targets
-      // to re-evaluate, but normal Tasks behind a Target run once then are cached
+      // to re-evaluate, but normal Tasks behind a CachedTarget run once then are cached
       check.apply(build.taskInput) ==> Right((1, 1))
       check.apply(build.taskInput) ==> Right((2, 1))
       check.apply(build.taskInput) ==> Right((3, 1))
     }
     "noInputs" - withEnv { (build, check) =>
       // Inputs always re-evaluate, including forcing downstream cached Targets
-      // to re-evaluate, but normal Tasks behind a Target run once then are cached
+      // to re-evaluate, but normal Tasks behind a CachedTarget run once then are cached
       check.apply(build.taskNoInput) ==> Right((1, 1))
       check.apply(build.taskNoInput) ==> Right((1, 0))
       check.apply(build.taskNoInput) ==> Right((1, 0))
diff --git a/main/test/src/mill/main/MainTests.scala b/main/test/src/mill/main/MainTests.scala
index 2fdf22ec688..0516104887f 100644
--- a/main/test/src/mill/main/MainTests.scala
+++ b/main/test/src/mill/main/MainTests.scala
@@ -1,18 +1,18 @@
 package mill.main
 
-import mill.define.{NamedTask, Segment, SelectMode}
+import mill.define.{Target, Segment, SelectMode}
 import mill.util.TestGraphs._
 import utest._
 object MainTests extends TestSuite {
 
   def check[T <: mill.define.BaseModule](module: T)(
       selectorString: String,
-      expected0: Either[String, Seq[T => NamedTask[_]]]
+      expected0: Either[String, Seq[T => Target[_]]]
   ) = checkSeq(module)(Seq(selectorString), expected0)
 
   def checkSeq[T <: mill.define.BaseModule](module: T)(
       selectorStrings: Seq[String],
-      expected0: Either[String, Seq[T => NamedTask[_]]]
+      expected0: Either[String, Seq[T => Target[_]]]
   ) = {
 
     val expected = expected0.map(_.map(_(module)))
diff --git a/main/test/src/mill/util/TestEvaluator.scala b/main/test/src/mill/util/TestEvaluator.scala
index ef3b315c8b1..37253576408 100644
--- a/main/test/src/mill/util/TestEvaluator.scala
+++ b/main/test/src/mill/util/TestEvaluator.scala
@@ -2,7 +2,7 @@ package mill.util
 
 import mill.testkit.MillTestKit
 import java.io.{InputStream, PrintStream}
-import mill.define.{Input, Target, Task}
+import mill.define.{Input, CachedTarget, Task}
 import mill.api.Result.OuterStack
 import mill.eval.Evaluator
 import mill.api.Strict.Agg
diff --git a/main/test/src/mill/util/TestUtil.scala b/main/test/src/mill/util/TestUtil.scala
index 9c4f921e605..e56b7e460fc 100644
--- a/main/test/src/mill/util/TestUtil.scala
+++ b/main/test/src/mill/util/TestUtil.scala
@@ -45,7 +45,7 @@ object TestUtil extends MillTestKit {
    */
   class TestTarget(inputs: Seq[Task[Int]], val pure: Boolean)(implicit ctx0: mill.define.Ctx)
       extends Test(inputs)
-      with Target[Int] {
+      with CachedTarget[Int] {
     val ctx = ctx0.withSegments(ctx0.segments ++ Seq(ctx0.segment))
     val readWrite = upickle.default.readwriter[Int]
 
diff --git a/main/testkit/src/mill/testkit/MillTestkit.scala b/main/testkit/src/mill/testkit/MillTestkit.scala
index 2fbe434b2a4..ec7c9a82b21 100644
--- a/main/testkit/src/mill/testkit/MillTestkit.scala
+++ b/main/testkit/src/mill/testkit/MillTestkit.scala
@@ -5,7 +5,7 @@ import mill.api.Result
 import mill.api.Result.OuterStack
 import mill.api.Strict.Agg
 import java.io.{InputStream, PrintStream}
-import mill.define.{Input, Target, Task}
+import mill.define.{Input, CachedTarget, Task}
 import mill.eval.Evaluator
 import language.experimental.macros
 import mill.api.{DummyInputStream, Result}
@@ -115,7 +115,7 @@ trait MillTestKit {
           Tuple2(
             evaluated.rawValues.head.asInstanceOf[Result.Success[T]].value,
             evaluated.evaluated.collect {
-              case t: Target[_]
+              case t: CachedTarget[_]
                   if module.millInternal.targets.contains(t)
                     && !t.isInstanceOf[Input[_]]
                     && !t.ctx.external => t
@@ -131,7 +131,7 @@ trait MillTestKit {
       }
     }
 
-    def fail(target: Target[_], expectedFailCount: Int, expectedRawValues: Seq[Result[_]]): Unit = {
+    def fail(target: CachedTarget[_], expectedFailCount: Int, expectedRawValues: Seq[Result[_]]): Unit = {
 
       val res = evaluator.evaluate(Agg(target))
 
diff --git a/scalajslib/test/src/mill/scalajslib/HelloJSWorldTests.scala b/scalajslib/test/src/mill/scalajslib/HelloJSWorldTests.scala
index 3f797a7b867..92b90f80e0d 100644
--- a/scalajslib/test/src/mill/scalajslib/HelloJSWorldTests.scala
+++ b/scalajslib/test/src/mill/scalajslib/HelloJSWorldTests.scala
@@ -199,7 +199,7 @@ object HelloJSWorldTests extends TestSuite {
       }
     }
 
-    def runTests(testTask: define.NamedTask[(String, Seq[TestRunner.Result])])
+    def runTests(testTask: define.Target[(String, Seq[TestRunner.Result])])
         : Map[String, Map[String, TestRunner.Result]] = {
       val Left(Result.Failure(_, Some(res))) = helloWorldEvaluator(testTask)
 
diff --git a/scalalib/test/src/mill/scalalib/HelloWorldTests.scala b/scalalib/test/src/mill/scalalib/HelloWorldTests.scala
index c37bfb4cb8d..fcbb19db54a 100644
--- a/scalalib/test/src/mill/scalalib/HelloWorldTests.scala
+++ b/scalalib/test/src/mill/scalalib/HelloWorldTests.scala
@@ -7,7 +7,7 @@ import scala.util.{Properties, Using}
 import scala.xml.NodeSeq
 import mill._
 import mill.api.Result
-import mill.define.{Input, NamedTask, Target}
+import mill.define.{Input, Target}
 import mill.eval.{Evaluator, EvaluatorPaths}
 import mill.modules.Assembly
 import mill.scalalib.publish.{VersionControl, _}
@@ -1225,13 +1225,13 @@ object HelloWorldTests extends TestSuite {
             // we reconstruct faulty behavior
             val Right((result, _)) = eval.apply(t)
             assert(
-              result.path.last == (t.asInstanceOf[NamedTask[_]].label + ".dest"),
+              result.path.last == (t.asInstanceOf[Target[_]].label + ".dest"),
               os.exists(result.path)
             )
             os.remove.all(result.path)
             val Right((result2, _)) = eval.apply(t)
             assert(
-              result2.path.last == (t.asInstanceOf[NamedTask[_]].label + ".dest"),
+              result2.path.last == (t.asInstanceOf[Target[_]].label + ".dest"),
               // as the result was cached but not checked, this path is missing
               os.exists(result2.path) == flip
             )
@@ -1244,13 +1244,13 @@ object HelloWorldTests extends TestSuite {
           // we reconstruct faulty behavior
           val Right((result, _)) = eval.apply(t)
           assert(
-            result.map(_.path.last) == Seq(t.asInstanceOf[NamedTask[_]].label + ".dest"),
+            result.map(_.path.last) == Seq(t.asInstanceOf[Target[_]].label + ".dest"),
             result.forall(p => os.exists(p.path))
           )
           result.foreach(p => os.remove.all(p.path))
           val Right((result2, _)) = eval.apply(t)
           assert(
-            result2.map(_.path.last) == Seq(t.asInstanceOf[NamedTask[_]].label + ".dest"),
+            result2.map(_.path.last) == Seq(t.asInstanceOf[Target[_]].label + ".dest"),
             // as the result was cached but not checked, this path is missing
             result2.forall(p => os.exists(p.path) == flip)
           )
@@ -1263,13 +1263,13 @@ object HelloWorldTests extends TestSuite {
           // we reconstruct faulty behavior
           val Right((result, _)) = eval.apply(t)
           assert(
-            result.map(_.path.last) == Agg(t.asInstanceOf[NamedTask[_]].label + ".dest"),
+            result.map(_.path.last) == Agg(t.asInstanceOf[Target[_]].label + ".dest"),
             result.forall(p => os.exists(p.path))
           )
           result.foreach(p => os.remove.all(p.path))
           val Right((result2, _)) = eval.apply(t)
           assert(
-            result2.map(_.path.last) == Agg(t.asInstanceOf[NamedTask[_]].label + ".dest"),
+            result2.map(_.path.last) == Agg(t.asInstanceOf[Target[_]].label + ".dest"),
             // as the result was cached but not checked, this path is missing
             result2.forall(p => os.exists(p.path) == flip)
           )
@@ -1283,13 +1283,13 @@ object HelloWorldTests extends TestSuite {
             // we reconstruct faulty behavior
             val Right((result, _)) = eval.apply(t)
             assert(
-              result._1.path.last == (t.asInstanceOf[NamedTask[_]].label + ".dest"),
+              result._1.path.last == (t.asInstanceOf[Target[_]].label + ".dest"),
               os.exists(result._1.path)
             )
             os.remove.all(result._1.path)
             val Right((result2, _)) = eval.apply(t)
             assert(
-              result2._1.path.last == (t.asInstanceOf[NamedTask[_]].label + ".dest"),
+              result2._1.path.last == (t.asInstanceOf[Target[_]].label + ".dest"),
               // as the result was cached but not checked, this path is missing
               os.exists(result2._1.path) == flip
             )
diff --git a/scalanativelib/test/src/mill/scalanativelib/HelloNativeWorldTests.scala b/scalanativelib/test/src/mill/scalanativelib/HelloNativeWorldTests.scala
index 480ddecdfc4..1d399df8c8a 100644
--- a/scalanativelib/test/src/mill/scalanativelib/HelloNativeWorldTests.scala
+++ b/scalanativelib/test/src/mill/scalanativelib/HelloNativeWorldTests.scala
@@ -154,7 +154,7 @@ object HelloNativeWorldTests extends TestSuite {
       )
     }
 
-    def runTests(testTask: define.NamedTask[(String, Seq[TestRunner.Result])])
+    def runTests(testTask: define.Target[(String, Seq[TestRunner.Result])])
         : Map[String, Map[String, TestRunner.Result]] = {
       val Left(Result.Failure(_, Some(res))) = helloWorldEvaluator(testTask)
 

From 7849a7f801faeaf73bb7b3dd5d81bb397a35e1e8 Mon Sep 17 00:00:00 2001
From: Li Haoyi <haoyi.sg@gmail.com>
Date: Sun, 2 Apr 2023 14:54:12 +0800
Subject: [PATCH 02/16] fix

---
 main/src/mill/main/ResolveSegments.scala | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/main/src/mill/main/ResolveSegments.scala b/main/src/mill/main/ResolveSegments.scala
index 0a26cc03711..b258f9a66ae 100644
--- a/main/src/mill/main/ResolveSegments.scala
+++ b/main/src/mill/main/ResolveSegments.scala
@@ -50,13 +50,19 @@ object ResolveSegments extends Resolve[Segments] {
         .reflectSingle[Target[_]](last)
         .map(t => Right(t.ctx.segments))
 
+    val command =
+      Resolve
+        .invokeCommand(obj, last, discover.asInstanceOf[Discover[Module]], rest)
+        .headOption
+        .map(_.map(_.ctx.segments))
+
     val module =
       obj.millInternal
         .reflectNestedObjects[Module]
         .find(_.millOuterCtx.segment == Segment.Label(last))
         .map(m => Right(m.millModuleSegments))
 
-    target orElse module match {
+    command orElse target orElse module match {
       case None =>
         Resolve.errorMsgLabel(
           singleModuleMeta(obj, discover, obj.millModuleSegments.value.isEmpty),

From 3da2dcb0b8fc0f82cfce3009611fc5070145e148 Mon Sep 17 00:00:00 2001
From: Li Haoyi <haoyi.sg@gmail.com>
Date: Sun, 2 Apr 2023 16:39:34 +0800
Subject: [PATCH 03/16] .

---
 main/core/src/mill/define/Task.scala          | 24 ++++-----
 .../src/mill/define/MacroErrorTests.scala     | 48 ++++++++---------
 main/test/src/mill/eval/TaskTests.scala       | 52 ++++++++++++++++++-
 3 files changed, 87 insertions(+), 37 deletions(-)

diff --git a/main/core/src/mill/define/Task.scala b/main/core/src/mill/define/Task.scala
index 0b40bf92894..635b1061520 100644
--- a/main/core/src/mill/define/Task.scala
+++ b/main/core/src/mill/define/Task.scala
@@ -144,10 +144,10 @@ object Target extends Applicative.Applyer[Task, Task, Result, mill.api.Ctx] {
     )
   }
 
-  def sources(values: Result[os.Path]*)(implicit ctx: mill.define.Ctx): Sources = macro sourcesImpl1
+  def sources(values: Result[os.Path]*)(implicit ctx: mill.define.Ctx): Target[Seq[PathRef]] = macro sourcesImpl1
 
   def sourcesImpl1(c: Context)(values: c.Expr[Result[os.Path]]*)(ctx: c.Expr[mill.define.Ctx])
-      : c.Expr[Sources] = {
+      : c.Expr[Target[Seq[PathRef]]] = {
     import c.universe._
     val wrapped =
       for (value <- values.toList)
@@ -168,11 +168,11 @@ object Target extends Applicative.Applyer[Task, Task, Result, mill.api.Ctx] {
     )
   }
 
-  def sources(values: Result[Seq[PathRef]])(implicit ctx: mill.define.Ctx): Sources =
+  def sources(values: Result[Seq[PathRef]])(implicit ctx: mill.define.Ctx): Target[Seq[PathRef]] =
     macro sourcesImpl2
 
   def sourcesImpl2(c: Context)(values: c.Expr[Result[Seq[PathRef]]])(ctx: c.Expr[mill.define.Ctx])
-      : c.Expr[Sources] = {
+      : c.Expr[Target[Seq[PathRef]]] = {
     import c.universe._
 
     val taskIsPrivate = isPrivateTargetOption(c)
@@ -187,10 +187,10 @@ object Target extends Applicative.Applyer[Task, Task, Result, mill.api.Ctx] {
       )
     )
   }
-  def source(value: Result[os.Path])(implicit ctx: mill.define.Ctx): Source = macro sourceImpl1
+  def source(value: Result[os.Path])(implicit ctx: mill.define.Ctx): Target[PathRef] = macro sourceImpl1
 
   def sourceImpl1(c: Context)(value: c.Expr[Result[os.Path]])(ctx: c.Expr[mill.define.Ctx])
-      : c.Expr[Source] = {
+      : c.Expr[Target[PathRef]] = {
     import c.universe._
 
     val wrapped =
@@ -200,7 +200,7 @@ object Target extends Applicative.Applyer[Task, Task, Result, mill.api.Ctx] {
 
     val taskIsPrivate = isPrivateTargetOption(c)
 
-    mill.moduledefs.Cacher.impl0[Source](c)(
+    mill.moduledefs.Cacher.impl0[Target[PathRef]](c)(
       reify(
         new Source(
           wrapped.splice,
@@ -211,15 +211,15 @@ object Target extends Applicative.Applyer[Task, Task, Result, mill.api.Ctx] {
     )
   }
 
-  def source(value: Result[PathRef])(implicit ctx: mill.define.Ctx): Source = macro sourceImpl2
+  def source(value: Result[PathRef])(implicit ctx: mill.define.Ctx): Target[PathRef] = macro sourceImpl2
 
   def sourceImpl2(c: Context)(value: c.Expr[Result[PathRef]])(ctx: c.Expr[mill.define.Ctx])
-      : c.Expr[Source] = {
+      : c.Expr[Target[PathRef]] = {
     import c.universe._
 
     val taskIsPrivate = isPrivateTargetOption(c)
 
-    mill.moduledefs.Cacher.impl0[Source](c)(
+    mill.moduledefs.Cacher.impl0[Target[PathRef]](c)(
       reify(
         new Source(
           Applicative.impl0[Task, PathRef, mill.api.Ctx](c)(value.tree).splice,
@@ -232,13 +232,13 @@ object Target extends Applicative.Applyer[Task, Task, Result, mill.api.Ctx] {
   def input[T](value: Result[T])(implicit
       w: upickle.default.Writer[T],
       ctx: mill.define.Ctx
-  ): Input[T] =
+  ): Target[T] =
     macro inputImpl[T]
 
   def inputImpl[T: c.WeakTypeTag](c: Context)(value: c.Expr[T])(
       w: c.Expr[upickle.default.Writer[T]],
       ctx: c.Expr[mill.define.Ctx]
-  ): c.Expr[Input[T]] = {
+  ): c.Expr[Target[T]] = {
     import c.universe._
 
     val taskIsPrivate = isPrivateTargetOption(c)
diff --git a/main/test/src/mill/define/MacroErrorTests.scala b/main/test/src/mill/define/MacroErrorTests.scala
index cdda22b6881..f02cd693c13 100644
--- a/main/test/src/mill/define/MacroErrorTests.scala
+++ b/main/test/src/mill/define/MacroErrorTests.scala
@@ -40,30 +40,30 @@ object MacroErrorTests extends TestSuite {
 //          e.pos.contains("def x() = ")
 //        )
 //      }
-      "input" - {
-        val e = compileError("""
-          object foo extends mill.util.TestUtil.BaseModule{
-            def y() = T.input{1}
-          }
-          mill.define.Discover[foo.type]
-        """)
-        assert(
-          e.msg.contains("`T.input` definitions must have 0 parameter lists"),
-          e.pos.contains("def y() = ")
-        )
-      }
-      "sources" - {
-        val e = compileError("""
-          object foo extends mill.util.TestUtil.BaseModule{
-            def z() = T.sources{os.pwd}
-          }
-          mill.define.Discover[foo.type]
-        """)
-        assert(
-          e.msg.contains("`T.sources` definitions must have 0 parameter lists"),
-          e.pos.contains("def z() = ")
-        )
-      }
+//      "input" - {
+//        val e = compileError("""
+//          object foo extends mill.util.TestUtil.BaseModule{
+//            def y() = T.input{1}
+//          }
+//          mill.define.Discover[foo.type]
+//        """)
+//        assert(
+//          e.msg.contains("`T.input` definitions must have 0 parameter lists"),
+//          e.pos.contains("def y() = ")
+//        )
+//      }
+//      "sources" - {
+//        val e = compileError("""
+//          object foo extends mill.util.TestUtil.BaseModule{
+//            def z() = T.sources{os.pwd}
+//          }
+//          mill.define.Discover[foo.type]
+//        """)
+//        assert(
+//          e.msg.contains("`T.sources` definitions must have 0 parameter lists"),
+//          e.pos.contains("def z() = ")
+//        )
+//      }
       "persistent" - {
         val e = compileError("""
           object foo extends mill.util.TestUtil.BaseModule{
diff --git a/main/test/src/mill/eval/TaskTests.scala b/main/test/src/mill/eval/TaskTests.scala
index bc7f0fbfe31..c6c22e01d78 100644
--- a/main/test/src/mill/eval/TaskTests.scala
+++ b/main/test/src/mill/eval/TaskTests.scala
@@ -7,7 +7,25 @@ import mill.util.{TestEvaluator, TestUtil}
 import utest.framework.TestPath
 
 trait TaskTests extends TestSuite {
-  trait Build extends TestUtil.BaseModule {
+  trait SuperBuild extends TestUtil.BaseModule {
+
+    var superBuildInputCount = 0
+
+    def superBuildInputOverrideWithConstant = T.input {
+      superBuildInputCount += 1
+      superBuildInputCount
+    }
+
+    def superBuildInputOverrideUsingSuper = T.input {
+      superBuildInputCount += 1
+      superBuildInputCount
+    }
+
+    def superBuildTargetOverrideWithInput = T {
+      1234
+    }
+  }
+  trait Build extends SuperBuild{
     var count = 0
     var changeOnceCount = 0
     var workerCloseCount = 0
@@ -89,6 +107,17 @@ trait TaskTests extends TestSuite {
       val w = changeOnceWorker()
       w.apply(1)
     }
+
+    override def superBuildInputOverrideWithConstant = T{ 123 }
+    override def superBuildInputOverrideUsingSuper = T{
+      123  + super.superBuildInputOverrideUsingSuper()
+    }
+
+    var superBuildTargetOverrideWithInputCount = 0
+    override def superBuildTargetOverrideWithInput = T.input {
+      superBuildTargetOverrideWithInputCount += 1
+      superBuildTargetOverrideWithInputCount
+    }
   }
 
   def withEnv(f: (Build, TestEvaluator) => Unit)(implicit tp: TestPath): Unit
@@ -192,6 +221,27 @@ trait TaskTests extends TestSuite {
         assert(wc.head != secondCached)
       }
     }
+
+
+    "overrideDifferentKind" - {
+      "inputWithTarget" - {
+        "notUsingSuper" - withEnv { (build, check) =>
+          check.apply(build.superBuildInputOverrideWithConstant) ==> Right((123, 1))
+          check.apply(build.superBuildInputOverrideWithConstant) ==> Right((123, 0))
+          check.apply(build.superBuildInputOverrideWithConstant) ==> Right((123, 0))
+        }
+        "usingSuper" - withEnv { (build, check) =>
+          check.apply(build.superBuildInputOverrideUsingSuper) ==> Right((124, 1))
+          check.apply(build.superBuildInputOverrideUsingSuper) ==> Right((125, 1))
+          check.apply(build.superBuildInputOverrideUsingSuper) ==> Right((126, 1))
+        }
+      }
+      "targetWithInput" - withEnv { (build, check) =>
+        check.apply(build.superBuildTargetOverrideWithInput) ==> Right((1, 0))
+        check.apply(build.superBuildTargetOverrideWithInput) ==> Right((2, 0))
+        check.apply(build.superBuildTargetOverrideWithInput) ==> Right((3, 0))
+      }
+    }
   }
 }
 

From 88876c09e5f6072c472beb2809dd96be0b3db6c6 Mon Sep 17 00:00:00 2001
From: Li Haoyi <haoyi.sg@gmail.com>
Date: Sun, 2 Apr 2023 16:54:10 +0800
Subject: [PATCH 04/16] .

---
 main/core/src/mill/define/Router.scala        |  6 +-
 main/core/src/mill/define/Task.scala          | 58 +++++++++----------
 main/core/src/mill/define/package.scala       |  8 +++
 main/core/src/mill/eval/Evaluator.scala       |  2 +-
 main/src/mill/main/RunScript.scala            |  4 +-
 main/test/src/mill/define/GraphTests.scala    |  2 +-
 .../src/mill/define/MacroErrorTests.scala     | 24 ++++----
 7 files changed, 56 insertions(+), 48 deletions(-)
 create mode 100644 main/core/src/mill/define/package.scala

diff --git a/main/core/src/mill/define/Router.scala b/main/core/src/mill/define/Router.scala
index c0f2f7d7349..537bfa42114 100644
--- a/main/core/src/mill/define/Router.scala
+++ b/main/core/src/mill/define/Router.scala
@@ -59,9 +59,9 @@ class Router(val ctx: blackbox.Context) extends mainargs.Macros(ctx) {
       overridesRoutes = {
         assertParamListCounts(
           methods,
-          (weakTypeOf[mill.define.Sources], 0, "`T.sources`"),
-          (weakTypeOf[mill.define.Input[_]], 0, "`T.input`"),
-          (weakTypeOf[mill.define.Persistent[_]], 0, "`T.persistent`"),
+          (weakTypeOf[mill.define.SourcesImpl], 0, "`T.sources`"),
+          (weakTypeOf[mill.define.InputImpl[_]], 0, "`T.input`"),
+          (weakTypeOf[mill.define.PersistentImpl[_]], 0, "`T.persistent`"),
           (weakTypeOf[mill.define.CachedTarget[_]], 0, "`T{...}`"),
           (weakTypeOf[mill.define.Command[_]], 1, "`T.command`")
         )
diff --git a/main/core/src/mill/define/Task.scala b/main/core/src/mill/define/Task.scala
index 635b1061520..b26b72a716b 100644
--- a/main/core/src/mill/define/Task.scala
+++ b/main/core/src/mill/define/Task.scala
@@ -34,9 +34,9 @@ abstract class Task[+T] extends Task.Ops[T] with Applyable[Task, T] {
 
   def flushDest: Boolean = true
 
-  def asTarget: Option[CachedTarget[T]] = None
+  def asTarget: Option[Target[T]] = None
   def asCommand: Option[Command[T]] = None
-  def asWorker: Option[Worker[T]] = None
+  def asWorker: Option[Target[T]] = None
   def self: Task[T] = this
 }
 
@@ -157,9 +157,9 @@ object Target extends Applicative.Applyer[Task, Task, Result, mill.api.Ctx] {
 
     val taskIsPrivate = isPrivateTargetOption(c)
 
-    mill.moduledefs.Cacher.impl0[Sources](c)(
+    mill.moduledefs.Cacher.impl0[SourcesImpl](c)(
       reify(
-        new Sources(
+        new SourcesImpl(
           Target.sequence(c.Expr[List[Task[PathRef]]](q"_root_.scala.List(..$wrapped)").splice),
           ctx.splice,
           taskIsPrivate.splice
@@ -177,9 +177,9 @@ object Target extends Applicative.Applyer[Task, Task, Result, mill.api.Ctx] {
 
     val taskIsPrivate = isPrivateTargetOption(c)
 
-    mill.moduledefs.Cacher.impl0[Sources](c)(
+    mill.moduledefs.Cacher.impl0[SourcesImpl](c)(
       reify(
-        new Sources(
+        new SourcesImpl(
           Applicative.impl0[Task, Seq[PathRef], mill.api.Ctx](c)(values.tree).splice,
           ctx.splice,
           taskIsPrivate.splice
@@ -202,7 +202,7 @@ object Target extends Applicative.Applyer[Task, Task, Result, mill.api.Ctx] {
 
     mill.moduledefs.Cacher.impl0[Target[PathRef]](c)(
       reify(
-        new Source(
+        new SourceImpl(
           wrapped.splice,
           ctx.splice,
           taskIsPrivate.splice
@@ -221,7 +221,7 @@ object Target extends Applicative.Applyer[Task, Task, Result, mill.api.Ctx] {
 
     mill.moduledefs.Cacher.impl0[Target[PathRef]](c)(
       reify(
-        new Source(
+        new SourceImpl(
           Applicative.impl0[Task, PathRef, mill.api.Ctx](c)(value.tree).splice,
           ctx.splice,
           taskIsPrivate.splice
@@ -243,9 +243,9 @@ object Target extends Applicative.Applyer[Task, Task, Result, mill.api.Ctx] {
 
     val taskIsPrivate = isPrivateTargetOption(c)
 
-    mill.moduledefs.Cacher.impl0[Input[T]](c)(
+    mill.moduledefs.Cacher.impl0[InputImpl[T]](c)(
       reify(
-        new Input[T](
+        new InputImpl[T](
           Applicative.impl[Task, T, mill.api.Ctx](c)(value).splice,
           ctx.splice,
           w.splice,
@@ -307,31 +307,31 @@ object Target extends Applicative.Applyer[Task, Task, Result, mill.api.Ctx] {
     )
   }
 
-  def worker[T](t: Task[T])(implicit ctx: mill.define.Ctx): Worker[T] = macro workerImpl1[T]
+  def worker[T](t: Task[T])(implicit ctx: mill.define.Ctx): Target[T] = macro workerImpl1[T]
 
   def workerImpl1[T: c.WeakTypeTag](c: Context)(t: c.Expr[Task[T]])(ctx: c.Expr[mill.define.Ctx])
-      : c.Expr[Worker[T]] = {
+      : c.Expr[Target[T]] = {
     import c.universe._
 
     val taskIsPrivate = isPrivateTargetOption(c)
 
-    mill.moduledefs.Cacher.impl0[Worker[T]](c)(
+    mill.moduledefs.Cacher.impl0[Target[T]](c)(
       reify(
-        new Worker[T](t.splice, ctx.splice, taskIsPrivate.splice)
+        new WorkerImpl[T](t.splice, ctx.splice, taskIsPrivate.splice)
       )
     )
   }
-  def worker[T](t: Result[T])(implicit ctx: mill.define.Ctx): Worker[T] = macro workerImpl2[T]
+  def worker[T](t: Result[T])(implicit ctx: mill.define.Ctx): Target[T] = macro workerImpl2[T]
 
   def workerImpl2[T: c.WeakTypeTag](c: Context)(t: c.Expr[T])(ctx: c.Expr[mill.define.Ctx])
-      : c.Expr[Worker[T]] = {
+      : c.Expr[Target[T]] = {
     import c.universe._
 
     val taskIsPrivate = isPrivateTargetOption(c)
 
-    mill.moduledefs.Cacher.impl0[Worker[T]](c)(
+    mill.moduledefs.Cacher.impl0[Target[T]](c)(
       reify(
-        new Worker[T](
+        new WorkerImpl[T](
           Applicative.impl[Task, T, mill.api.Ctx](c)(t).splice,
           ctx.splice,
           taskIsPrivate.splice
@@ -342,20 +342,20 @@ object Target extends Applicative.Applyer[Task, Task, Result, mill.api.Ctx] {
 
   def task[T](t: Result[T]): Task[T] = macro Applicative.impl[Task, T, mill.api.Ctx]
 
-  def persistent[T](t: Result[T])(implicit rw: RW[T], ctx: mill.define.Ctx): Persistent[T] =
+  def persistent[T](t: Result[T])(implicit rw: RW[T], ctx: mill.define.Ctx): Target[T] =
     macro persistentImpl[T]
 
   def persistentImpl[T: c.WeakTypeTag](c: Context)(t: c.Expr[T])(
       rw: c.Expr[RW[T]],
       ctx: c.Expr[mill.define.Ctx]
-  ): c.Expr[Persistent[T]] = {
+  ): c.Expr[PersistentImpl[T]] = {
     import c.universe._
 
     val taskIsPrivate = isPrivateTargetOption(c)
 
-    mill.moduledefs.Cacher.impl0[Persistent[T]](c)(
+    mill.moduledefs.Cacher.impl0[PersistentImpl[T]](c)(
       reify(
-        new Persistent[T](
+        new PersistentImpl[T](
           Applicative.impl[Task, T, mill.api.Ctx](c)(t).splice,
           ctx.splice,
           rw.splice,
@@ -403,13 +403,13 @@ class Command[+T](
   override def asCommand = Some(this)
 }
 
-class Worker[+T](t: Task[T], ctx0: mill.define.Ctx, isPrivate: Option[Boolean])
+class WorkerImpl[+T](t: Task[T], ctx0: mill.define.Ctx, isPrivate: Option[Boolean])
     extends TargetImpl[T](ctx0, t, isPrivate) {
   override def flushDest = false
   override def asWorker = Some(this)
 }
 
-class Persistent[+T](
+class PersistentImpl[+T](
     t: Task[T],
     ctx0: mill.define.Ctx,
     readWrite: RW[_],
@@ -419,7 +419,7 @@ class Persistent[+T](
   override def flushDest = false
 }
 
-class Input[T](
+class InputImpl[T](
     t: Task[T],
     ctx0: mill.define.Ctx,
     val writer: upickle.default.Writer[_],
@@ -428,16 +428,16 @@ class Input[T](
   override def sideHash = util.Random.nextInt()
 }
 
-class Sources(t: Task[Seq[PathRef]], ctx0: mill.define.Ctx, isPrivate: Option[Boolean])
-    extends Input[Seq[PathRef]](
+class SourcesImpl(t: Task[Seq[PathRef]], ctx0: mill.define.Ctx, isPrivate: Option[Boolean])
+    extends InputImpl[Seq[PathRef]](
       t,
       ctx0,
       upickle.default.SeqLikeWriter[Seq, PathRef],
       isPrivate
     )
 
-class Source(t: Task[PathRef], ctx0: mill.define.Ctx, isPrivate: Option[Boolean])
-    extends Input[PathRef](
+class SourceImpl(t: Task[PathRef], ctx0: mill.define.Ctx, isPrivate: Option[Boolean])
+    extends InputImpl[PathRef](
       t,
       ctx0,
       PathRef.jsonFormatter,
diff --git a/main/core/src/mill/define/package.scala b/main/core/src/mill/define/package.scala
new file mode 100644
index 00000000000..6cb8c145dc9
--- /dev/null
+++ b/main/core/src/mill/define/package.scala
@@ -0,0 +1,8 @@
+package mill
+package object define{
+  type Source = define.Target[mill.api.PathRef]
+  type Sources = define.Target[Seq[mill.api.PathRef]]
+  type Input[T] = define.Target[T]
+  type Persistent[T] = define.Target[T]
+  type Worker[T] = define.Target[T]
+}
diff --git a/main/core/src/mill/eval/Evaluator.scala b/main/core/src/mill/eval/Evaluator.scala
index f86c50d269e..af0619f93e1 100644
--- a/main/core/src/mill/eval/Evaluator.scala
+++ b/main/core/src/mill/eval/Evaluator.scala
@@ -30,7 +30,7 @@ case class Labelled[T](task: Target[T], segments: Segments) {
   }
   def writer: Option[default.Writer[T]] = task match {
     case t: mill.define.Command[T] => Some(t.writer.asInstanceOf[upickle.default.Writer[T]])
-    case t: mill.define.Input[T] => Some(t.writer.asInstanceOf[upickle.default.Writer[T]])
+    case t: mill.define.InputImpl[T] => Some(t.writer.asInstanceOf[upickle.default.Writer[T]])
     case t: CachedTarget[T] => Some(t.readWrite.asInstanceOf[upickle.default.ReadWriter[T]])
     case _ => None
   }
diff --git a/main/src/mill/main/RunScript.scala b/main/src/mill/main/RunScript.scala
index d366d12203a..e8e198fc8ff 100644
--- a/main/src/mill/main/RunScript.scala
+++ b/main/src/mill/main/RunScript.scala
@@ -169,8 +169,8 @@ object RunScript {
     val watched = evaluated.results
       .iterator
       .collect {
-        case (t: Sources, Result.Success(ps: Seq[PathRef])) => ps
-        case (t: Source, Result.Success(p: PathRef)) => Seq(p)
+        case (t: SourcesImpl, Result.Success(ps: Seq[PathRef])) => ps
+        case (t: SourceImpl, Result.Success(p: PathRef)) => Seq(p)
       }
       .flatten
       .toSeq
diff --git a/main/test/src/mill/define/GraphTests.scala b/main/test/src/mill/define/GraphTests.scala
index f4e931fbe83..bc02ed479c3 100644
--- a/main/test/src/mill/define/GraphTests.scala
+++ b/main/test/src/mill/define/GraphTests.scala
@@ -88,7 +88,7 @@ object GraphTests extends TestSuite {
           val grouping = grouped.lookupKey(terminal)
           assert(
             grouping.size == expectedSize,
-            grouping.flatMap(_.asTarget: Option[CachedTarget[_]]).filter(important.contains) == Agg(
+            grouping.flatMap(_.asTarget: Option[Target[_]]).filter(important.contains) == Agg(
               terminal
             )
           )
diff --git a/main/test/src/mill/define/MacroErrorTests.scala b/main/test/src/mill/define/MacroErrorTests.scala
index f02cd693c13..240fa5b5714 100644
--- a/main/test/src/mill/define/MacroErrorTests.scala
+++ b/main/test/src/mill/define/MacroErrorTests.scala
@@ -64,18 +64,18 @@ object MacroErrorTests extends TestSuite {
 //          e.pos.contains("def z() = ")
 //        )
 //      }
-      "persistent" - {
-        val e = compileError("""
-          object foo extends mill.util.TestUtil.BaseModule{
-            def a() = T.persistent{1}
-          }
-          mill.define.Discover[foo.type]
-        """)
-        assert(
-          e.msg.contains("`T.persistent` definitions must have 0 parameter lists"),
-          e.pos.contains("def a() = ")
-        )
-      }
+//      "persistent" - {
+//        val e = compileError("""
+//          object foo extends mill.util.TestUtil.BaseModule{
+//            def a() = T.persistent{1}
+//          }
+//          mill.define.Discover[foo.type]
+//        """)
+//        assert(
+//          e.msg.contains("`T.persistent` definitions must have 0 parameter lists"),
+//          e.pos.contains("def a() = ")
+//        )
+//      }
     }
     "badTmacro" - {
       // Make sure we can reference values from outside the T{...} block as part

From 58269ae376ec92dbd191133a0d74fe34c5a4e708 Mon Sep 17 00:00:00 2001
From: Li Haoyi <haoyi.sg@gmail.com>
Date: Sun, 2 Apr 2023 16:58:21 +0800
Subject: [PATCH 05/16] .

---
 build.sc | 76 ++++++++++++++++++++++++++++----------------------------
 1 file changed, 38 insertions(+), 38 deletions(-)

diff --git a/build.sc b/build.sc
index fcaa023bf79..1e0e27a948f 100644
--- a/build.sc
+++ b/build.sc
@@ -689,44 +689,44 @@ object contrib extends MillModule {
     override def testModuleDeps: Seq[JavaModule] = super.testModuleDeps ++ Seq(scalalib)
   }
 
-//  object playlib extends MillModule {
-//    override def moduleDeps = Seq(twirllib, playlib.api)
-//    override def compileModuleDeps = Seq(scalalib)
-//
-//    override def testArgs = T {
-//      val mapping = Map(
-//        "MILL_CONTRIB_PLAYLIB_ROUTECOMPILER_WORKER_2_6" -> worker("2.6").assembly().path,
-//        "MILL_CONTRIB_PLAYLIB_ROUTECOMPILER_WORKER_2_7" -> worker("2.7").assembly().path,
-//        "MILL_CONTRIB_PLAYLIB_ROUTECOMPILER_WORKER_2_8" -> worker("2.8").assembly().path,
-//        "TEST_PLAY_VERSION_2_6" -> Deps.Play_2_6.playVersion,
-//        "TEST_PLAY_VERSION_2_7" -> Deps.Play_2_7.playVersion,
-//        "TEST_PLAY_VERSION_2_8" -> Deps.Play_2_8.playVersion
-//      )
-//
-//      scalalib.worker.testArgs() ++
-//        scalalib.backgroundwrapper.testArgs() ++
-//        (for ((k, v) <- mapping.to(Seq)) yield s"-D$k=$v")
-//    }
-//    override def testModuleDeps: Seq[JavaModule] = super.testModuleDeps ++ Seq(scalalib)
-//
-//    object api extends MillPublishModule
-//
-//    object worker extends Cross[WorkerModule](Deps.play.keys.toSeq: _*)
-//    class WorkerModule(playBinary: String) extends MillInternalModule {
-//      override def sources = T.sources {
-//        // We want to avoid duplicating code as long as the Play APIs allow.
-//        // But if newer Play versions introduce incompatibilities,
-//        // just remove the shared source dir for that worker and implement directly.
-//        Seq(PathRef(millSourcePath / os.up / "src-shared")) ++ super.sources()
-//      }
-//      override def scalaVersion = Deps.play(playBinary).scalaVersion
-//      override def moduleDeps = Seq(playlib.api)
-//      override def ivyDeps = Agg(
-//        Deps.osLib,
-//        Deps.play(playBinary).routesCompiler
-//      )
-//    }
-//  }
+  object playlib extends MillModule {
+    override def moduleDeps = Seq(twirllib, playlib.api)
+    override def compileModuleDeps = Seq(scalalib)
+
+    override def testArgs = T {
+      val mapping = Map(
+        "MILL_CONTRIB_PLAYLIB_ROUTECOMPILER_WORKER_2_6" -> worker("2.6").assembly().path,
+        "MILL_CONTRIB_PLAYLIB_ROUTECOMPILER_WORKER_2_7" -> worker("2.7").assembly().path,
+        "MILL_CONTRIB_PLAYLIB_ROUTECOMPILER_WORKER_2_8" -> worker("2.8").assembly().path,
+        "TEST_PLAY_VERSION_2_6" -> Deps.Play_2_6.playVersion,
+        "TEST_PLAY_VERSION_2_7" -> Deps.Play_2_7.playVersion,
+        "TEST_PLAY_VERSION_2_8" -> Deps.Play_2_8.playVersion
+      )
+
+      scalalib.worker.testArgs() ++
+        scalalib.backgroundwrapper.testArgs() ++
+        (for ((k, v) <- mapping.to(Seq)) yield s"-D$k=$v")
+    }
+    override def testModuleDeps: Seq[JavaModule] = super.testModuleDeps ++ Seq(scalalib)
+
+    object api extends MillPublishModule
+
+    object worker extends Cross[WorkerModule](Deps.play.keys.toSeq: _*)
+    class WorkerModule(playBinary: String) extends MillInternalModule {
+      override def sources = T.sources {
+        // We want to avoid duplicating code as long as the Play APIs allow.
+        // But if newer Play versions introduce incompatibilities,
+        // just remove the shared source dir for that worker and implement directly.
+        Seq(PathRef(millSourcePath / os.up / "src-shared")) ++ super.sources()
+      }
+      override def scalaVersion = Deps.play(playBinary).scalaVersion
+      override def moduleDeps = Seq(playlib.api)
+      override def ivyDeps = Agg(
+        Deps.osLib,
+        Deps.play(playBinary).routesCompiler
+      )
+    }
+  }
 
   object scalapblib extends MillModule {
     override def compileModuleDeps = Seq(scalalib)

From 21d2a6146e114d48a06caa462d8e17ccce46dd27 Mon Sep 17 00:00:00 2001
From: Li Haoyi <haoyi.sg@gmail.com>
Date: Sun, 2 Apr 2023 17:20:18 +0800
Subject: [PATCH 06/16] .

---
 .../src/mill/bsp/worker/MillBuildServer.scala |  2 +-
 main/api/src/mill/api/Ctx.scala               |  4 +-
 main/core/src/mill/define/Applicative.scala   |  4 +-
 main/core/src/mill/define/Router.scala        |  2 +-
 main/core/src/mill/define/Task.scala          | 38 +++++++++----------
 main/core/src/mill/eval/Evaluator.scala       |  4 +-
 main/src/mill/main/MainModule.scala           |  4 +-
 .../src/mill/define/ApplicativeTests.scala    |  2 +-
 main/test/src/mill/define/GraphTests.scala    |  2 +-
 .../src/mill/define/MacroErrorTests.scala     |  9 +++--
 main/test/src/mill/eval/EvaluationTests.scala | 10 ++---
 .../src/mill/eval/JavaCompileJarTests.scala   |  4 +-
 main/test/src/mill/eval/TaskTests.scala       |  4 +-
 main/test/src/mill/util/TestEvaluator.scala   |  5 ---
 .../src/mill/testkit/MillTestkit.scala        |  6 +--
 15 files changed, 49 insertions(+), 51 deletions(-)

diff --git a/bsp/worker/src/mill/bsp/worker/MillBuildServer.scala b/bsp/worker/src/mill/bsp/worker/MillBuildServer.scala
index e63fe23fb1b..feb21f05edc 100644
--- a/bsp/worker/src/mill/bsp/worker/MillBuildServer.scala
+++ b/bsp/worker/src/mill/bsp/worker/MillBuildServer.scala
@@ -665,7 +665,7 @@ class MillBuildServer(
               logger = new MillBspLogger(client, cleanTask.hashCode, evaluator.baseLogger)
             )
             if (cleanResult.failing.keyCount > 0) (
-              msg + s" CachedTarget ${compileTargetName} could not be cleaned. See message from mill: \n" +
+              msg + s" Target ${compileTargetName} could not be cleaned. See message from mill: \n" +
                 (cleanResult.results(cleanTask) match {
                   case fail: Result.Failure[Any] => fail.msg + "\n"
                   case _ => "could not retrieve message"
diff --git a/main/api/src/mill/api/Ctx.scala b/main/api/src/mill/api/Ctx.scala
index d78cd5f76f9..b78e017e265 100644
--- a/main/api/src/mill/api/Ctx.scala
+++ b/main/api/src/mill/api/Ctx.scala
@@ -5,10 +5,10 @@ import scala.language.implicitConversions
 import os.Path
 
 /**
- * Provides access to various resources in the context of a currently execution CachedTarget.
+ * Provides access to various resources in the context of a currently execution Target.
  */
 object Ctx {
-  @compileTimeOnly("CachedTarget.ctx() / T.ctx() / T.* APIs can only be used with a T{...} block")
+  @compileTimeOnly("Target.ctx() / T.ctx() / T.* APIs can only be used with a T{...} block")
   @ImplicitStub
   implicit def taskCtx: Ctx = ???
 
diff --git a/main/core/src/mill/define/Applicative.scala b/main/core/src/mill/define/Applicative.scala
index 6c50b1663c3..ff212a7a30e 100644
--- a/main/core/src/mill/define/Applicative.scala
+++ b/main/core/src/mill/define/Applicative.scala
@@ -18,7 +18,7 @@ object Applicative {
     def apply[T](t: M[T]): T
   }
   object ApplyHandler {
-    @compileTimeOnly("CachedTarget#apply() can only be used with a T{...} block")
+    @compileTimeOnly("Target#apply() can only be used with a T{...} block")
     implicit def defaultApplyHandler[M[+_]]: ApplyHandler[M] = ???
   }
   trait Applyable[M[+_], +T] {
@@ -64,7 +64,7 @@ object Applicative {
           val banned0 = banned.next()
           c.abort(
             banned0.pos,
-            "CachedTarget#apply() call cannot use `" + banned0.symbol + "` defined within the T{...} block"
+            "Target#apply() call cannot use `" + banned0.symbol + "` defined within the T{...} block"
           )
         }
         val tempName = c.freshName(TermName("tmp"))
diff --git a/main/core/src/mill/define/Router.scala b/main/core/src/mill/define/Router.scala
index 537bfa42114..6f5e60285e0 100644
--- a/main/core/src/mill/define/Router.scala
+++ b/main/core/src/mill/define/Router.scala
@@ -62,7 +62,7 @@ class Router(val ctx: blackbox.Context) extends mainargs.Macros(ctx) {
           (weakTypeOf[mill.define.SourcesImpl], 0, "`T.sources`"),
           (weakTypeOf[mill.define.InputImpl[_]], 0, "`T.input`"),
           (weakTypeOf[mill.define.PersistentImpl[_]], 0, "`T.persistent`"),
-          (weakTypeOf[mill.define.CachedTarget[_]], 0, "`T{...}`"),
+          (weakTypeOf[mill.define.TargetImpl[_]], 0, "`T{...}`"),
           (weakTypeOf[mill.define.Command[_]], 1, "`T.command`")
         )
 
diff --git a/main/core/src/mill/define/Task.scala b/main/core/src/mill/define/Task.scala
index b26b72a716b..b6b1ad84f85 100644
--- a/main/core/src/mill/define/Task.scala
+++ b/main/core/src/mill/define/Task.scala
@@ -12,12 +12,12 @@ import scala.reflect.macros.blackbox.Context
  * single output of type [[T]].
  *
  * Generally not instantiated manually, but instead constructed via the
- * [[CachedTarget.apply]] & similar macros.
+ * [[Target.apply]] & similar macros.
  */
 abstract class Task[+T] extends Task.Ops[T] with Applyable[Task, T] {
 
   /**
-   * What other Targets does this CachedTarget depend on?
+   * What other Targets does this Target depend on?
    */
   val inputs: Seq[Task[_]]
 
@@ -52,7 +52,7 @@ trait Target[+T] extends Task[T] {
   def isPrivate: Option[Boolean] = None
 }
 trait CachedTarget[+T] extends Target[T] {
-  override def asTarget: Option[CachedTarget[T]] = Some(this)
+  override def asTarget: Option[Target[T]] = Some(this)
   def readWrite: RW[_]
 }
 
@@ -73,16 +73,16 @@ object Target extends Applicative.Applyer[Task, Task, Result, mill.api.Ctx] {
   def targetImpl[T: c.WeakTypeTag](c: Context)(t: c.Expr[T])(
       rw: c.Expr[RW[T]],
       ctx: c.Expr[mill.define.Ctx]
-  ): c.Expr[CachedTarget[T]] = {
+  ): c.Expr[Target[T]] = {
     import c.universe._
 
     val taskIsPrivate = isPrivateTargetOption(c)
 
     val lhs = Applicative.impl0[Task, T, mill.api.Ctx](c)(reify(Result.Success(t.splice)).tree)
 
-    mill.moduledefs.Cacher.impl0[CachedTarget[T]](c)(
+    mill.moduledefs.Cacher.impl0[Target[T]](c)(
       reify(
-        new CachedTargetImpl[T](
+        new TargetImpl[T](
           lhs.splice,
           ctx.splice,
           rw.splice,
@@ -104,14 +104,14 @@ object Target extends Applicative.Applyer[Task, Task, Result, mill.api.Ctx] {
   def targetResultImpl[T: c.WeakTypeTag](c: Context)(t: c.Expr[Result[T]])(
       rw: c.Expr[RW[T]],
       ctx: c.Expr[mill.define.Ctx]
-  ): c.Expr[CachedTarget[T]] = {
+  ): c.Expr[Target[T]] = {
     import c.universe._
 
     val taskIsPrivate = isPrivateTargetOption(c)
 
-    mill.moduledefs.Cacher.impl0[CachedTarget[T]](c)(
+    mill.moduledefs.Cacher.impl0[Target[T]](c)(
       reify(
-        new CachedTargetImpl[T](
+        new TargetImpl[T](
           Applicative.impl0[Task, T, mill.api.Ctx](c)(t.tree).splice,
           ctx.splice,
           rw.splice,
@@ -127,14 +127,14 @@ object Target extends Applicative.Applyer[Task, Task, Result, mill.api.Ctx] {
   def targetTaskImpl[T: c.WeakTypeTag](c: Context)(t: c.Expr[Task[T]])(
       rw: c.Expr[RW[T]],
       ctx: c.Expr[mill.define.Ctx]
-  ): c.Expr[CachedTarget[T]] = {
+  ): c.Expr[Target[T]] = {
     import c.universe._
 
     val taskIsPrivate = isPrivateTargetOption(c)
 
-    mill.moduledefs.Cacher.impl0[CachedTarget[T]](c)(
+    mill.moduledefs.Cacher.impl0[Target[T]](c)(
       reify(
-        new CachedTargetImpl[T](
+        new TargetImpl[T](
           t.splice,
           ctx.splice,
           rw.splice,
@@ -375,7 +375,7 @@ object Target extends Applicative.Applyer[Task, Task, Result, mill.api.Ctx] {
   }
 }
 
-abstract class TargetImpl[+T](
+abstract class TargetImplBase[+T](
     ctx0: mill.define.Ctx,
     t: Task[T],
     override val isPrivate: Option[Boolean]
@@ -385,12 +385,12 @@ abstract class TargetImpl[+T](
   val inputs = Seq(t)
 }
 
-class CachedTargetImpl[+T](
+class TargetImpl[+T](
     t: Task[T],
     ctx0: mill.define.Ctx,
     override val readWrite: RW[_],
     isPrivate: Option[Boolean]
-) extends TargetImpl[T](ctx0, t, isPrivate)
+) extends TargetImplBase[T](ctx0, t, isPrivate)
     with CachedTarget[T] {}
 
 class Command[+T](
@@ -399,12 +399,12 @@ class Command[+T](
     val writer: W[_],
     val cls: Class[_],
     isPrivate: Option[Boolean]
-) extends TargetImpl[T](ctx0, t, isPrivate) {
+) extends TargetImplBase[T](ctx0, t, isPrivate) {
   override def asCommand = Some(this)
 }
 
 class WorkerImpl[+T](t: Task[T], ctx0: mill.define.Ctx, isPrivate: Option[Boolean])
-    extends TargetImpl[T](ctx0, t, isPrivate) {
+    extends TargetImplBase[T](ctx0, t, isPrivate) {
   override def flushDest = false
   override def asWorker = Some(this)
 }
@@ -414,7 +414,7 @@ class PersistentImpl[+T](
     ctx0: mill.define.Ctx,
     readWrite: RW[_],
     isPrivate: Option[Boolean]
-) extends CachedTargetImpl[T](t, ctx0, readWrite, isPrivate) {
+) extends TargetImpl[T](t, ctx0, readWrite, isPrivate) {
 
   override def flushDest = false
 }
@@ -424,7 +424,7 @@ class InputImpl[T](
     ctx0: mill.define.Ctx,
     val writer: upickle.default.Writer[_],
     isPrivate: Option[Boolean]
-) extends TargetImpl[T](ctx0, t, isPrivate) {
+) extends TargetImplBase[T](ctx0, t, isPrivate) {
   override def sideHash = util.Random.nextInt()
 }
 
diff --git a/main/core/src/mill/eval/Evaluator.scala b/main/core/src/mill/eval/Evaluator.scala
index af0619f93e1..c127faecb27 100644
--- a/main/core/src/mill/eval/Evaluator.scala
+++ b/main/core/src/mill/eval/Evaluator.scala
@@ -25,13 +25,13 @@ import scala.util.control.NonFatal
 
 case class Labelled[T](task: Target[T], segments: Segments) {
   def format: Option[default.ReadWriter[T]] = task match {
-    case t: CachedTarget[T] => Some(t.readWrite.asInstanceOf[upickle.default.ReadWriter[T]])
+    case t: TargetImpl[T] => Some(t.readWrite.asInstanceOf[upickle.default.ReadWriter[T]])
     case _ => None
   }
   def writer: Option[default.Writer[T]] = task match {
     case t: mill.define.Command[T] => Some(t.writer.asInstanceOf[upickle.default.Writer[T]])
     case t: mill.define.InputImpl[T] => Some(t.writer.asInstanceOf[upickle.default.Writer[T]])
-    case t: CachedTarget[T] => Some(t.readWrite.asInstanceOf[upickle.default.ReadWriter[T]])
+    case t: TargetImpl[T] => Some(t.readWrite.asInstanceOf[upickle.default.ReadWriter[T]])
     case _ => None
   }
 }
diff --git a/main/src/mill/main/MainModule.scala b/main/src/mill/main/MainModule.scala
index 2e441dc15e0..eef28cc3f2a 100644
--- a/main/src/mill/main/MainModule.scala
+++ b/main/src/mill/main/MainModule.scala
@@ -5,7 +5,7 @@ import mainargs.TokensReader
 import java.util.concurrent.LinkedBlockingQueue
 import mill.{BuildInfo, T}
 import mill.api.{Ctx, PathRef, Result, internal}
-import mill.define.{Command, Target, Segments, SelectMode, CachedTarget, Task}
+import mill.define.{Command, Segments, SelectMode, Target, TargetImpl, Task}
 import mill.eval.{Evaluator, EvaluatorPaths}
 import mill.util.{PrintLogger, Watched}
 import pprint.{Renderer, Tree, Truncated}
@@ -180,7 +180,7 @@ trait MainModule extends mill.Module {
       def rec(t: Task[_]): Seq[Segments] = {
         if (seen(t)) Nil // do nothing
         else t match {
-          case t: CachedTarget[_] if evaluator.rootModule.millInternal.targets.contains(t) =>
+          case t: TargetImpl[_] if evaluator.rootModule.millInternal.targets.contains(t) =>
             Seq(t.ctx.segments)
           case _ =>
             seen.add(t)
diff --git a/main/test/src/mill/define/ApplicativeTests.scala b/main/test/src/mill/define/ApplicativeTests.scala
index 46e03036f06..1eede908af2 100644
--- a/main/test/src/mill/define/ApplicativeTests.scala
+++ b/main/test/src/mill/define/ApplicativeTests.scala
@@ -27,7 +27,7 @@ object ApplicativeTests extends TestSuite {
       value
     }
   }
-  @compileTimeOnly("CachedTarget.ctx() can only be used with a T{...} block")
+  @compileTimeOnly("Target.ctx() can only be used with a T{...} block")
   @ImplicitStub
   implicit def taskCtx: String = ???
 
diff --git a/main/test/src/mill/define/GraphTests.scala b/main/test/src/mill/define/GraphTests.scala
index bc02ed479c3..a298f5e4a0a 100644
--- a/main/test/src/mill/define/GraphTests.scala
+++ b/main/test/src/mill/define/GraphTests.scala
@@ -79,7 +79,7 @@ object GraphTests extends TestSuite {
 
         val important = important0.map(_(base))
         val grouped = Graph.groupAroundImportantTargets(topoSorted) {
-          case t: CachedTarget[_] if important.contains(t) => t: Target[_]
+          case t: TargetImpl[_] if important.contains(t) => t: Target[_]
         }
         val flattened = Agg.from(grouped.values().flatMap(_.items))
 
diff --git a/main/test/src/mill/define/MacroErrorTests.scala b/main/test/src/mill/define/MacroErrorTests.scala
index 240fa5b5714..4e16fac061e 100644
--- a/main/test/src/mill/define/MacroErrorTests.scala
+++ b/main/test/src/mill/define/MacroErrorTests.scala
@@ -28,6 +28,9 @@ object MacroErrorTests extends TestSuite {
           e.pos.contains("def w = ")
         )
       }
+
+      // WIP getting this error reporting working again
+
 //      "target" - {
 //        val e = compileError("""
 //          object foo extends mill.util.TestUtil.BaseModule{
@@ -79,7 +82,7 @@ object MacroErrorTests extends TestSuite {
     }
     "badTmacro" - {
       // Make sure we can reference values from outside the T{...} block as part
-      // of our `CachedTarget#apply()` calls, but we cannot reference any values that
+      // of our `Target#apply()` calls, but we cannot reference any values that
       // come from inside the T{...} block
       "pos" - {
         val e = compileError("""
@@ -99,7 +102,7 @@ object MacroErrorTests extends TestSuite {
       "neg" - {
 
         val expectedMsg =
-          "CachedTarget#apply() call cannot use `value n` defined within the T{...} block"
+          "Target#apply() call cannot use `value n` defined within the T{...} block"
         val err = compileError("""new Module{
           def a = T{ 1 }
           val arr = Array(a)
@@ -115,7 +118,7 @@ object MacroErrorTests extends TestSuite {
       "neg2" - {
 
         val expectedMsg =
-          "CachedTarget#apply() call cannot use `value x` defined within the T{...} block"
+          "Target#apply() call cannot use `value x` defined within the T{...} block"
         val err = compileError("""new Module{
           def a = T{ 1 }
           val arr = Array(a)
diff --git a/main/test/src/mill/eval/EvaluationTests.scala b/main/test/src/mill/eval/EvaluationTests.scala
index 36600fc90f5..de8c8d32f1c 100644
--- a/main/test/src/mill/eval/EvaluationTests.scala
+++ b/main/test/src/mill/eval/EvaluationTests.scala
@@ -1,7 +1,7 @@
 package mill.eval
 
 import mill.util.TestUtil.{Test, test}
-import mill.define.{Discover, Graph, CachedTarget, Task}
+import mill.define.{Discover, Graph, TargetImpl, Task}
 import mill.{Module, T}
 import mill.util.{DummyLogger, TestEvaluator, TestGraphs, TestUtil}
 import mill.api.Strict.Agg
@@ -181,14 +181,14 @@ class EvaluationTests(threadCount: Option[Int]) extends TestSuite {
         import separateGroups._
         val checker = new Checker(separateGroups)
         val evaled1 = checker.evaluator.evaluate(Agg(right, left))
-        val filtered1 = evaled1.evaluated.filter(_.isInstanceOf[CachedTarget[_]])
+        val filtered1 = evaled1.evaluated.filter(_.isInstanceOf[TargetImpl[_]])
         assert(filtered1.toSeq.sortBy(_.toString) == Seq(change, left, right).sortBy(_.toString))
         val evaled2 = checker.evaluator.evaluate(Agg(right, left))
-        val filtered2 = evaled2.evaluated.filter(_.isInstanceOf[CachedTarget[_]])
+        val filtered2 = evaled2.evaluated.filter(_.isInstanceOf[TargetImpl[_]])
         assert(filtered2 == Agg())
         change.counter += 1
         val evaled3 = checker.evaluator.evaluate(Agg(right, left))
-        val filtered3 = evaled3.evaluated.filter(_.isInstanceOf[CachedTarget[_]])
+        val filtered3 = evaled3.evaluated.filter(_.isInstanceOf[TargetImpl[_]])
         assert(filtered3 == Agg(change, right))
 
       }
@@ -337,7 +337,7 @@ class EvaluationTests(threadCount: Option[Int]) extends TestSuite {
         // But if `up` changes, the entire block of downstream tasks needs to
         // recompute together, including `middle` which doesn't depend on `up`,
         // because tasks have no cached value that can be used. `right`, which
-        // is a cached CachedTarget, does not recompute
+        // is a cached Target, does not recompute
         up.inputs(0).asInstanceOf[Test].counter += 1
         check(down, expValue = 10102, expEvaled = Agg(up, down), extraEvaled = 4)
         assert(leftCount == 2, middleCount == 2, rightCount == 1)
diff --git a/main/test/src/mill/eval/JavaCompileJarTests.scala b/main/test/src/mill/eval/JavaCompileJarTests.scala
index a617f5d36c8..9839929413a 100644
--- a/main/test/src/mill/eval/JavaCompileJarTests.scala
+++ b/main/test/src/mill/eval/JavaCompileJarTests.scala
@@ -1,6 +1,6 @@
 package mill.eval
 
-import mill.define.{Discover, Input, CachedTarget, Task}
+import mill.define.{Discover, Input, Target, Task}
 import mill.modules.Jvm
 import mill.api.Ctx.Dest
 import mill.{Module, T}
@@ -87,7 +87,7 @@ object JavaCompileJarTests extends TestSuite {
       // exactly the same so no re-jarring.
       append(sourceRootPath / "Foo.java", " ")
       // Note that `sourceRoot` and `resourceRoot` never turn up in the `expected`
-      // list, because they are `Source`s not `CachedTarget`s
+      // list, because they are `Source`s not `Target`s
       check(targets = Agg(jar), expected = Agg( /*sourceRoot, */ allSources, classFiles))
 
       // Appending a new class changes the classfiles, which forces us to
diff --git a/main/test/src/mill/eval/TaskTests.scala b/main/test/src/mill/eval/TaskTests.scala
index c6c22e01d78..77a295f8d99 100644
--- a/main/test/src/mill/eval/TaskTests.scala
+++ b/main/test/src/mill/eval/TaskTests.scala
@@ -126,14 +126,14 @@ trait TaskTests extends TestSuite {
 
     "inputs" - withEnv { (build, check) =>
       // Inputs always re-evaluate, including forcing downstream cached Targets
-      // to re-evaluate, but normal Tasks behind a CachedTarget run once then are cached
+      // to re-evaluate, but normal Tasks behind a Target run once then are cached
       check.apply(build.taskInput) ==> Right((1, 1))
       check.apply(build.taskInput) ==> Right((2, 1))
       check.apply(build.taskInput) ==> Right((3, 1))
     }
     "noInputs" - withEnv { (build, check) =>
       // Inputs always re-evaluate, including forcing downstream cached Targets
-      // to re-evaluate, but normal Tasks behind a CachedTarget run once then are cached
+      // to re-evaluate, but normal Tasks behind a Target run once then are cached
       check.apply(build.taskNoInput) ==> Right((1, 1))
       check.apply(build.taskNoInput) ==> Right((1, 0))
       check.apply(build.taskNoInput) ==> Right((1, 0))
diff --git a/main/test/src/mill/util/TestEvaluator.scala b/main/test/src/mill/util/TestEvaluator.scala
index 37253576408..5da300dc515 100644
--- a/main/test/src/mill/util/TestEvaluator.scala
+++ b/main/test/src/mill/util/TestEvaluator.scala
@@ -1,12 +1,7 @@
 package mill.util
 
-import mill.testkit.MillTestKit
 import java.io.{InputStream, PrintStream}
-import mill.define.{Input, CachedTarget, Task}
-import mill.api.Result.OuterStack
 import mill.eval.Evaluator
-import mill.api.Strict.Agg
-import utest.assert
 import utest.framework.TestPath
 
 import language.experimental.macros
diff --git a/main/testkit/src/mill/testkit/MillTestkit.scala b/main/testkit/src/mill/testkit/MillTestkit.scala
index ec7c9a82b21..ad4e59eba82 100644
--- a/main/testkit/src/mill/testkit/MillTestkit.scala
+++ b/main/testkit/src/mill/testkit/MillTestkit.scala
@@ -5,7 +5,7 @@ import mill.api.Result
 import mill.api.Result.OuterStack
 import mill.api.Strict.Agg
 import java.io.{InputStream, PrintStream}
-import mill.define.{Input, CachedTarget, Task}
+import mill.define.{Input, Task}
 import mill.eval.Evaluator
 import language.experimental.macros
 import mill.api.{DummyInputStream, Result}
@@ -115,7 +115,7 @@ trait MillTestKit {
           Tuple2(
             evaluated.rawValues.head.asInstanceOf[Result.Success[T]].value,
             evaluated.evaluated.collect {
-              case t: CachedTarget[_]
+              case t: TargetImpl[_]
                   if module.millInternal.targets.contains(t)
                     && !t.isInstanceOf[Input[_]]
                     && !t.ctx.external => t
@@ -131,7 +131,7 @@ trait MillTestKit {
       }
     }
 
-    def fail(target: CachedTarget[_], expectedFailCount: Int, expectedRawValues: Seq[Result[_]]): Unit = {
+    def fail(target: Target[_], expectedFailCount: Int, expectedRawValues: Seq[Result[_]]): Unit = {
 
       val res = evaluator.evaluate(Agg(target))
 

From 2014d5104790ebea17e9ed5c45938e53dd4e19d5 Mon Sep 17 00:00:00 2001
From: Li Haoyi <haoyi.sg@gmail.com>
Date: Sun, 2 Apr 2023 17:55:33 +0800
Subject: [PATCH 07/16] .

---
 main/core/src/mill/eval/Evaluator.scala           |  6 +++---
 main/src/mill/main/MainModule.scala               |  4 ++--
 main/src/mill/main/ResolveSegments.scala          |  1 -
 main/test/src/mill/define/GraphTests.scala        |  2 +-
 main/test/src/mill/eval/EvaluationTests.scala     |  8 ++++----
 main/test/src/mill/eval/JavaCompileJarTests.scala |  4 ++++
 main/testkit/src/mill/testkit/MillTestkit.scala   | 10 ++++++----
 7 files changed, 20 insertions(+), 15 deletions(-)

diff --git a/main/core/src/mill/eval/Evaluator.scala b/main/core/src/mill/eval/Evaluator.scala
index c127faecb27..6cc9130ff53 100644
--- a/main/core/src/mill/eval/Evaluator.scala
+++ b/main/core/src/mill/eval/Evaluator.scala
@@ -25,13 +25,13 @@ import scala.util.control.NonFatal
 
 case class Labelled[T](task: Target[T], segments: Segments) {
   def format: Option[default.ReadWriter[T]] = task match {
-    case t: TargetImpl[T] => Some(t.readWrite.asInstanceOf[upickle.default.ReadWriter[T]])
+    case t: CachedTarget[T] => Some(t.readWrite.asInstanceOf[upickle.default.ReadWriter[T]])
     case _ => None
   }
   def writer: Option[default.Writer[T]] = task match {
     case t: mill.define.Command[T] => Some(t.writer.asInstanceOf[upickle.default.Writer[T]])
     case t: mill.define.InputImpl[T] => Some(t.writer.asInstanceOf[upickle.default.Writer[T]])
-    case t: TargetImpl[T] => Some(t.readWrite.asInstanceOf[upickle.default.ReadWriter[T]])
+    case t: CachedTarget[T] => Some(t.readWrite.asInstanceOf[upickle.default.ReadWriter[T]])
     case _ => None
   }
 }
@@ -615,7 +615,7 @@ class Evaluator private (_home: os.Path,
       newResults(task) = for (v <- res) yield {
         (
           v,
-          if (task.isInstanceOf[Worker[_]]) inputsHash
+          if (task.isInstanceOf[WorkerImpl[_]]) inputsHash
           else v.##
         )
       }
diff --git a/main/src/mill/main/MainModule.scala b/main/src/mill/main/MainModule.scala
index eef28cc3f2a..889df153fb6 100644
--- a/main/src/mill/main/MainModule.scala
+++ b/main/src/mill/main/MainModule.scala
@@ -5,7 +5,7 @@ import mainargs.TokensReader
 import java.util.concurrent.LinkedBlockingQueue
 import mill.{BuildInfo, T}
 import mill.api.{Ctx, PathRef, Result, internal}
-import mill.define.{Command, Segments, SelectMode, Target, TargetImpl, Task}
+import mill.define.{CachedTarget, Command, Segments, SelectMode, Target, TargetImpl, Task}
 import mill.eval.{Evaluator, EvaluatorPaths}
 import mill.util.{PrintLogger, Watched}
 import pprint.{Renderer, Tree, Truncated}
@@ -180,7 +180,7 @@ trait MainModule extends mill.Module {
       def rec(t: Task[_]): Seq[Segments] = {
         if (seen(t)) Nil // do nothing
         else t match {
-          case t: TargetImpl[_] if evaluator.rootModule.millInternal.targets.contains(t) =>
+          case t: CachedTarget[_] if evaluator.rootModule.millInternal.targets.contains(t) =>
             Seq(t.ctx.segments)
           case _ =>
             seen.add(t)
diff --git a/main/src/mill/main/ResolveSegments.scala b/main/src/mill/main/ResolveSegments.scala
index b258f9a66ae..7418ee67576 100644
--- a/main/src/mill/main/ResolveSegments.scala
+++ b/main/src/mill/main/ResolveSegments.scala
@@ -43,7 +43,6 @@ object ResolveSegments extends Resolve[Segments] {
       discover: Discover[_],
       rest: Seq[String]
   ): Either[String, Seq[Segments]] = {
-
     val target =
       obj
         .millInternal
diff --git a/main/test/src/mill/define/GraphTests.scala b/main/test/src/mill/define/GraphTests.scala
index a298f5e4a0a..bc02ed479c3 100644
--- a/main/test/src/mill/define/GraphTests.scala
+++ b/main/test/src/mill/define/GraphTests.scala
@@ -79,7 +79,7 @@ object GraphTests extends TestSuite {
 
         val important = important0.map(_(base))
         val grouped = Graph.groupAroundImportantTargets(topoSorted) {
-          case t: TargetImpl[_] if important.contains(t) => t: Target[_]
+          case t: CachedTarget[_] if important.contains(t) => t: Target[_]
         }
         val flattened = Agg.from(grouped.values().flatMap(_.items))
 
diff --git a/main/test/src/mill/eval/EvaluationTests.scala b/main/test/src/mill/eval/EvaluationTests.scala
index de8c8d32f1c..de3cbe11e39 100644
--- a/main/test/src/mill/eval/EvaluationTests.scala
+++ b/main/test/src/mill/eval/EvaluationTests.scala
@@ -1,7 +1,7 @@
 package mill.eval
 
 import mill.util.TestUtil.{Test, test}
-import mill.define.{Discover, Graph, TargetImpl, Task}
+import mill.define.{CachedTarget, Discover, Graph, TargetImpl, Task}
 import mill.{Module, T}
 import mill.util.{DummyLogger, TestEvaluator, TestGraphs, TestUtil}
 import mill.api.Strict.Agg
@@ -181,14 +181,14 @@ class EvaluationTests(threadCount: Option[Int]) extends TestSuite {
         import separateGroups._
         val checker = new Checker(separateGroups)
         val evaled1 = checker.evaluator.evaluate(Agg(right, left))
-        val filtered1 = evaled1.evaluated.filter(_.isInstanceOf[TargetImpl[_]])
+        val filtered1 = evaled1.evaluated.filter(_.isInstanceOf[CachedTarget[_]])
         assert(filtered1.toSeq.sortBy(_.toString) == Seq(change, left, right).sortBy(_.toString))
         val evaled2 = checker.evaluator.evaluate(Agg(right, left))
-        val filtered2 = evaled2.evaluated.filter(_.isInstanceOf[TargetImpl[_]])
+        val filtered2 = evaled2.evaluated.filter(_.isInstanceOf[CachedTarget[_]])
         assert(filtered2 == Agg())
         change.counter += 1
         val evaled3 = checker.evaluator.evaluate(Agg(right, left))
-        val filtered3 = evaled3.evaluated.filter(_.isInstanceOf[TargetImpl[_]])
+        val filtered3 = evaled3.evaluated.filter(_.isInstanceOf[CachedTarget[_]])
         assert(filtered3 == Agg(change, right))
 
       }
diff --git a/main/test/src/mill/eval/JavaCompileJarTests.scala b/main/test/src/mill/eval/JavaCompileJarTests.scala
index 9839929413a..765474d0608 100644
--- a/main/test/src/mill/eval/JavaCompileJarTests.scala
+++ b/main/test/src/mill/eval/JavaCompileJarTests.scala
@@ -72,11 +72,15 @@ object JavaCompileJarTests extends TestSuite {
 
       def append(path: os.Path, txt: String) = os.write.append(path, txt)
 
+      println("=" * 150)
+
       check(
         targets = Agg(jar),
         expected = Agg(allSources, classFiles, jar)
       )
 
+      println("=" * 150)
+
       // Re-running with no changes results in nothing being evaluated
       check(targets = Agg(jar), expected = Agg())
       // Appending an empty string gets ignored due to file-content hashing
diff --git a/main/testkit/src/mill/testkit/MillTestkit.scala b/main/testkit/src/mill/testkit/MillTestkit.scala
index ad4e59eba82..b39bd4ff73e 100644
--- a/main/testkit/src/mill/testkit/MillTestkit.scala
+++ b/main/testkit/src/mill/testkit/MillTestkit.scala
@@ -115,9 +115,9 @@ trait MillTestKit {
           Tuple2(
             evaluated.rawValues.head.asInstanceOf[Result.Success[T]].value,
             evaluated.evaluated.collect {
-              case t: TargetImpl[_]
+              case t: CachedTarget[_]
                   if module.millInternal.targets.contains(t)
-                    && !t.isInstanceOf[Input[_]]
+                    && !t.isInstanceOf[InputImpl[_]]
                     && !t.ctx.external => t
               case t: mill.define.Command[_] => t
             }.size
@@ -148,11 +148,13 @@ trait MillTestKit {
     }
 
     def check(targets: Agg[Task[_]], expected: Agg[Task[_]]): Unit = {
-      val evaluated = evaluator.evaluate(targets)
+      val targets2 = evaluator.evaluate(targets)
         .evaluated
         .flatMap(_.asTarget)
+
+      val evaluated = targets2
         .filter(module.millInternal.targets.contains)
-        .filter(!_.isInstanceOf[Input[_]])
+        .filter(!_.isInstanceOf[InputImpl[_]])
       assert(
         evaluated == expected,
         s"evaluated is not equal expected. evaluated=${evaluated}, expected=${expected}"

From a1a3f48f2d40192eaa8e498adb7382ea5a221d4a Mon Sep 17 00:00:00 2001
From: Li Haoyi <haoyi.sg@gmail.com>
Date: Sun, 2 Apr 2023 20:41:09 +0800
Subject: [PATCH 08/16] .

---
 main/core/src/mill/define/Router.scala        | 18 ++--
 .../src/mill/define/MacroErrorTests.scala     | 96 +++++++++----------
 2 files changed, 54 insertions(+), 60 deletions(-)

diff --git a/main/core/src/mill/define/Router.scala b/main/core/src/mill/define/Router.scala
index 6f5e60285e0..da9a22dfb95 100644
--- a/main/core/src/mill/define/Router.scala
+++ b/main/core/src/mill/define/Router.scala
@@ -39,17 +39,14 @@ class Router(val ctx: blackbox.Context) extends mainargs.Macros(ctx) {
         cases: (Type, Int, String)*
     ): Unit = {
       for (m <- methods.toList) {
-        for ((tt, n, label) <- cases) {
-          if (
-            m.returnType <:< tt &&
-            m.paramLists.length != n
-          ) {
-            c.abort(
+        cases
+          .find{case (tt, n, label) => m.returnType <:< tt}
+          .foreach{case (tt, n, label) =>
+            if (m.paramLists.length != n) c.abort(
               m.pos,
               s"$label definitions must have $n parameter list" + (if (n == 1) "" else "s")
             )
           }
-        }
       }
     }
     val mapping = for {
@@ -59,11 +56,8 @@ class Router(val ctx: blackbox.Context) extends mainargs.Macros(ctx) {
       overridesRoutes = {
         assertParamListCounts(
           methods,
-          (weakTypeOf[mill.define.SourcesImpl], 0, "`T.sources`"),
-          (weakTypeOf[mill.define.InputImpl[_]], 0, "`T.input`"),
-          (weakTypeOf[mill.define.PersistentImpl[_]], 0, "`T.persistent`"),
-          (weakTypeOf[mill.define.TargetImpl[_]], 0, "`T{...}`"),
-          (weakTypeOf[mill.define.Command[_]], 1, "`T.command`")
+          (weakTypeOf[mill.define.Command[_]], 1, "`T.command`"),
+          (weakTypeOf[mill.define.Target[_]], 0, "Target"),
         )
 
         for {
diff --git a/main/test/src/mill/define/MacroErrorTests.scala b/main/test/src/mill/define/MacroErrorTests.scala
index 4e16fac061e..9ec8e7fad5b 100644
--- a/main/test/src/mill/define/MacroErrorTests.scala
+++ b/main/test/src/mill/define/MacroErrorTests.scala
@@ -31,54 +31,54 @@ object MacroErrorTests extends TestSuite {
 
       // WIP getting this error reporting working again
 
-//      "target" - {
-//        val e = compileError("""
-//          object foo extends mill.util.TestUtil.BaseModule{
-//            def x() = T{1}
-//          }
-//          mill.define.Discover[foo.type]
-//        """)
-//        assert(
-//          e.msg.contains("`T{...}` definitions must have 0 parameter lists"),
-//          e.pos.contains("def x() = ")
-//        )
-//      }
-//      "input" - {
-//        val e = compileError("""
-//          object foo extends mill.util.TestUtil.BaseModule{
-//            def y() = T.input{1}
-//          }
-//          mill.define.Discover[foo.type]
-//        """)
-//        assert(
-//          e.msg.contains("`T.input` definitions must have 0 parameter lists"),
-//          e.pos.contains("def y() = ")
-//        )
-//      }
-//      "sources" - {
-//        val e = compileError("""
-//          object foo extends mill.util.TestUtil.BaseModule{
-//            def z() = T.sources{os.pwd}
-//          }
-//          mill.define.Discover[foo.type]
-//        """)
-//        assert(
-//          e.msg.contains("`T.sources` definitions must have 0 parameter lists"),
-//          e.pos.contains("def z() = ")
-//        )
-//      }
-//      "persistent" - {
-//        val e = compileError("""
-//          object foo extends mill.util.TestUtil.BaseModule{
-//            def a() = T.persistent{1}
-//          }
-//          mill.define.Discover[foo.type]
-//        """)
-//        assert(
-//          e.msg.contains("`T.persistent` definitions must have 0 parameter lists"),
-//          e.pos.contains("def a() = ")
-//        )
-//      }
+      "target" - {
+        val e = compileError("""
+          object foo extends mill.util.TestUtil.BaseModule{
+            def x() = T{1}
+          }
+          mill.define.Discover[foo.type]
+        """)
+        assert(
+          e.msg.contains("Target definitions must have 0 parameter lists"),
+          e.pos.contains("def x() = ")
+        )
+      }
+      "input" - {
+        val e = compileError("""
+          object foo extends mill.util.TestUtil.BaseModule{
+            def y() = T.input{1}
+          }
+          mill.define.Discover[foo.type]
+        """)
+        assert(
+          e.msg.contains("Target definitions must have 0 parameter lists"),
+          e.pos.contains("def y() = ")
+        )
+      }
+      "sources" - {
+        val e = compileError("""
+          object foo extends mill.util.TestUtil.BaseModule{
+            def z() = T.sources{os.pwd}
+          }
+          mill.define.Discover[foo.type]
+        """)
+        assert(
+          e.msg.contains("Target definitions must have 0 parameter lists"),
+          e.pos.contains("def z() = ")
+        )
+      }
+      "persistent" - {
+        val e = compileError("""
+          object foo extends mill.util.TestUtil.BaseModule{
+            def a() = T.persistent{1}
+          }
+          mill.define.Discover[foo.type]
+        """)
+        assert(
+          e.msg.contains("Target definitions must have 0 parameter lists"),
+          e.pos.contains("def a() = ")
+        )
+      }
     }
     "badTmacro" - {
       // Make sure we can reference values from outside the T{...} block as part

From f05a2974b418d1f4b1dc7876a2d44909cd8f2137 Mon Sep 17 00:00:00 2001
From: Li Haoyi <haoyi.sg@gmail.com>
Date: Mon, 3 Apr 2023 10:20:19 +0800
Subject: [PATCH 09/16] kill CachedTarget

---
 main/core/src/mill/define/Task.scala          | 11 ++++-----
 main/core/src/mill/eval/Evaluator.scala       |  4 ++--
 main/src/mill/main/MainModule.scala           |  4 ++--
 main/test/src/mill/define/GraphTests.scala    |  2 +-
 main/test/src/mill/eval/EvaluationTests.scala |  8 +++----
 main/test/src/mill/util/TestUtil.scala        | 23 +++++++++++++++----
 .../src/mill/testkit/MillTestkit.scala        |  2 +-
 7 files changed, 32 insertions(+), 22 deletions(-)

diff --git a/main/core/src/mill/define/Task.scala b/main/core/src/mill/define/Task.scala
index b6b1ad84f85..1ac3d369495 100644
--- a/main/core/src/mill/define/Task.scala
+++ b/main/core/src/mill/define/Task.scala
@@ -51,10 +51,6 @@ trait Target[+T] extends Task[T] {
   override def toString = ctx.segments.render
   def isPrivate: Option[Boolean] = None
 }
-trait CachedTarget[+T] extends Target[T] {
-  override def asTarget: Option[Target[T]] = Some(this)
-  def readWrite: RW[_]
-}
 
 object Target extends Applicative.Applyer[Task, Task, Result, mill.api.Ctx] {
   // convenience
@@ -388,10 +384,11 @@ abstract class TargetImplBase[+T](
 class TargetImpl[+T](
     t: Task[T],
     ctx0: mill.define.Ctx,
-    override val readWrite: RW[_],
+    val readWrite: RW[_],
     isPrivate: Option[Boolean]
-) extends TargetImplBase[T](ctx0, t, isPrivate)
-    with CachedTarget[T] {}
+) extends TargetImplBase[T](ctx0, t, isPrivate) {
+  override def asTarget: Option[Target[T]] = Some(this)
+}
 
 class Command[+T](
     t: Task[T],
diff --git a/main/core/src/mill/eval/Evaluator.scala b/main/core/src/mill/eval/Evaluator.scala
index 6cc9130ff53..2d6a020af6a 100644
--- a/main/core/src/mill/eval/Evaluator.scala
+++ b/main/core/src/mill/eval/Evaluator.scala
@@ -25,13 +25,13 @@ import scala.util.control.NonFatal
 
 case class Labelled[T](task: Target[T], segments: Segments) {
   def format: Option[default.ReadWriter[T]] = task match {
-    case t: CachedTarget[T] => Some(t.readWrite.asInstanceOf[upickle.default.ReadWriter[T]])
+    case t: TargetImpl[T] => Some(t.readWrite.asInstanceOf[upickle.default.ReadWriter[T]])
     case _ => None
   }
   def writer: Option[default.Writer[T]] = task match {
     case t: mill.define.Command[T] => Some(t.writer.asInstanceOf[upickle.default.Writer[T]])
     case t: mill.define.InputImpl[T] => Some(t.writer.asInstanceOf[upickle.default.Writer[T]])
-    case t: CachedTarget[T] => Some(t.readWrite.asInstanceOf[upickle.default.ReadWriter[T]])
+    case t: TargetImpl[T] => Some(t.readWrite.asInstanceOf[upickle.default.ReadWriter[T]])
     case _ => None
   }
 }
diff --git a/main/src/mill/main/MainModule.scala b/main/src/mill/main/MainModule.scala
index 889df153fb6..eef28cc3f2a 100644
--- a/main/src/mill/main/MainModule.scala
+++ b/main/src/mill/main/MainModule.scala
@@ -5,7 +5,7 @@ import mainargs.TokensReader
 import java.util.concurrent.LinkedBlockingQueue
 import mill.{BuildInfo, T}
 import mill.api.{Ctx, PathRef, Result, internal}
-import mill.define.{CachedTarget, Command, Segments, SelectMode, Target, TargetImpl, Task}
+import mill.define.{Command, Segments, SelectMode, Target, TargetImpl, Task}
 import mill.eval.{Evaluator, EvaluatorPaths}
 import mill.util.{PrintLogger, Watched}
 import pprint.{Renderer, Tree, Truncated}
@@ -180,7 +180,7 @@ trait MainModule extends mill.Module {
       def rec(t: Task[_]): Seq[Segments] = {
         if (seen(t)) Nil // do nothing
         else t match {
-          case t: CachedTarget[_] if evaluator.rootModule.millInternal.targets.contains(t) =>
+          case t: TargetImpl[_] if evaluator.rootModule.millInternal.targets.contains(t) =>
             Seq(t.ctx.segments)
           case _ =>
             seen.add(t)
diff --git a/main/test/src/mill/define/GraphTests.scala b/main/test/src/mill/define/GraphTests.scala
index bc02ed479c3..a298f5e4a0a 100644
--- a/main/test/src/mill/define/GraphTests.scala
+++ b/main/test/src/mill/define/GraphTests.scala
@@ -79,7 +79,7 @@ object GraphTests extends TestSuite {
 
         val important = important0.map(_(base))
         val grouped = Graph.groupAroundImportantTargets(topoSorted) {
-          case t: CachedTarget[_] if important.contains(t) => t: Target[_]
+          case t: TargetImpl[_] if important.contains(t) => t: Target[_]
         }
         val flattened = Agg.from(grouped.values().flatMap(_.items))
 
diff --git a/main/test/src/mill/eval/EvaluationTests.scala b/main/test/src/mill/eval/EvaluationTests.scala
index de3cbe11e39..de8c8d32f1c 100644
--- a/main/test/src/mill/eval/EvaluationTests.scala
+++ b/main/test/src/mill/eval/EvaluationTests.scala
@@ -1,7 +1,7 @@
 package mill.eval
 
 import mill.util.TestUtil.{Test, test}
-import mill.define.{CachedTarget, Discover, Graph, TargetImpl, Task}
+import mill.define.{Discover, Graph, TargetImpl, Task}
 import mill.{Module, T}
 import mill.util.{DummyLogger, TestEvaluator, TestGraphs, TestUtil}
 import mill.api.Strict.Agg
@@ -181,14 +181,14 @@ class EvaluationTests(threadCount: Option[Int]) extends TestSuite {
         import separateGroups._
         val checker = new Checker(separateGroups)
         val evaled1 = checker.evaluator.evaluate(Agg(right, left))
-        val filtered1 = evaled1.evaluated.filter(_.isInstanceOf[CachedTarget[_]])
+        val filtered1 = evaled1.evaluated.filter(_.isInstanceOf[TargetImpl[_]])
         assert(filtered1.toSeq.sortBy(_.toString) == Seq(change, left, right).sortBy(_.toString))
         val evaled2 = checker.evaluator.evaluate(Agg(right, left))
-        val filtered2 = evaled2.evaluated.filter(_.isInstanceOf[CachedTarget[_]])
+        val filtered2 = evaled2.evaluated.filter(_.isInstanceOf[TargetImpl[_]])
         assert(filtered2 == Agg())
         change.counter += 1
         val evaled3 = checker.evaluator.evaluate(Agg(right, left))
-        val filtered3 = evaled3.evaluated.filter(_.isInstanceOf[CachedTarget[_]])
+        val filtered3 = evaled3.evaluated.filter(_.isInstanceOf[TargetImpl[_]])
         assert(filtered3 == Agg(change, right))
 
       }
diff --git a/main/test/src/mill/util/TestUtil.scala b/main/test/src/mill/util/TestUtil.scala
index e56b7e460fc..3dabf7aead8 100644
--- a/main/test/src/mill/util/TestUtil.scala
+++ b/main/test/src/mill/util/TestUtil.scala
@@ -43,13 +43,26 @@ object TestUtil extends MillTestKit {
    * controlled externally, so you can construct arbitrary dataflow graphs and
    * test how changes propagate.
    */
-  class TestTarget(inputs: Seq[Task[Int]], val pure: Boolean)(implicit ctx0: mill.define.Ctx)
-      extends Test(inputs)
-      with CachedTarget[Int] {
-    val ctx = ctx0.withSegments(ctx0.segments ++ Seq(ctx0.segment))
-    val readWrite = upickle.default.readwriter[Int]
+  class TestTarget(taskInputs: Seq[Task[Int]], val pure: Boolean)(implicit ctx0: mill.define.Ctx)
+      extends TargetImpl[Int](
+        null,
+        ctx0,
+        upickle.default.readwriter[Int],
+        None
+      ){
+    override def evaluate(args: mill.api.Ctx) = testTask.evaluate(args)
+    override val inputs = taskInputs
+    val testTask = new Test(taskInputs)
+    def counter_=(i: Int) = testTask.counter = i
+    def counter = testTask.counter
+    def failure_=(s: Option[String]) = testTask.failure = s
+    def failure = testTask.failure
+    def exception_=(s: Option[Throwable]) = testTask.exception = s
+    def exception = testTask.exception
 
+    override def sideHash = testTask.sideHash
   }
+
   def checkTopological(targets: Agg[Task[_]]) = {
     val seen = mutable.Set.empty[Task[_]]
     for (t <- targets.indexed.reverseIterator) {
diff --git a/main/testkit/src/mill/testkit/MillTestkit.scala b/main/testkit/src/mill/testkit/MillTestkit.scala
index b39bd4ff73e..a930e816b66 100644
--- a/main/testkit/src/mill/testkit/MillTestkit.scala
+++ b/main/testkit/src/mill/testkit/MillTestkit.scala
@@ -115,7 +115,7 @@ trait MillTestKit {
           Tuple2(
             evaluated.rawValues.head.asInstanceOf[Result.Success[T]].value,
             evaluated.evaluated.collect {
-              case t: CachedTarget[_]
+              case t: TargetImpl[_]
                   if module.millInternal.targets.contains(t)
                     && !t.isInstanceOf[InputImpl[_]]
                     && !t.ctx.external => t

From 1a9686e1f7de0cde8dee167d49a9d0186d97b8be Mon Sep 17 00:00:00 2001
From: Li Haoyi <haoyi.sg@gmail.com>
Date: Mon, 3 Apr 2023 10:32:42 +0800
Subject: [PATCH 10/16] cleanup

---
 main/core/src/mill/define/Task.scala          | 146 ++++++++----------
 .../src/mill/testkit/MillTestkit.scala        |   1 -
 2 files changed, 67 insertions(+), 80 deletions(-)

diff --git a/main/core/src/mill/define/Task.scala b/main/core/src/mill/define/Task.scala
index 1ac3d369495..f7b2cc6c44a 100644
--- a/main/core/src/mill/define/Task.scala
+++ b/main/core/src/mill/define/Task.scala
@@ -40,8 +40,55 @@ abstract class Task[+T] extends Task.Ops[T] with Applyable[Task, T] {
   def self: Task[T] = this
 }
 
-trait Target[+T] extends Task[T] {
-  def ctx: mill.define.Ctx
+object Task {
+
+  abstract class Ops[+T] { this: Task[T] =>
+    def map[V](f: T => V) = new Task.Mapped(this, f)
+
+    def filter(f: T => Boolean) = this
+    def withFilter(f: T => Boolean) = this
+    def zip[V](other: Task[V]) = new Task.Zipped(this, other)
+
+  }
+
+  class Sequence[+T](inputs0: Seq[Task[T]]) extends Task[Seq[T]] {
+    val inputs = inputs0
+    def evaluate(args: mill.api.Ctx) = {
+      for (i <- 0 until args.length)
+        yield args(i).asInstanceOf[T]
+    }
+  }
+  class TraverseCtx[+T, V](
+                            inputs0: Seq[Task[T]],
+                            f: (IndexedSeq[T], mill.api.Ctx) => Result[V]
+                          ) extends Task[V] {
+    val inputs = inputs0
+    def evaluate(args: mill.api.Ctx) = {
+      f(
+        for (i <- 0 until args.length)
+          yield args(i).asInstanceOf[T],
+        args
+      )
+    }
+  }
+  class Mapped[+T, +V](source: Task[T], f: T => V) extends Task[V] {
+    def evaluate(args: mill.api.Ctx) = f(args(0))
+    val inputs = List(source)
+  }
+  class Zipped[+T, +V](source1: Task[T], source2: Task[V]) extends Task[(T, V)] {
+    def evaluate(args: mill.api.Ctx) = (args(0), args(1))
+    val inputs = List(source1, source2)
+  }
+}
+
+/**
+ * Represents a task that can be referenced by its path segments.
+ */
+class Target[+T](
+    t: Task[T],
+    ctx0: mill.define.Ctx,
+    val isPrivate: Option[Boolean]
+) extends Task[T] {
   def label: String = ctx.segment match {
     case Segment.Label(v) => v
     case Segment.Cross(_) => throw new IllegalArgumentException(
@@ -49,7 +96,11 @@ trait Target[+T] extends Task[T] {
       )
   }
   override def toString = ctx.segments.render
-  def isPrivate: Option[Boolean] = None
+
+  def evaluate(args: mill.api.Ctx) = args[T](0)
+
+  val ctx = ctx0.withSegments(segments = ctx0.segments ++ Seq(ctx0.segment))
+  val inputs = Seq(t)
 }
 
 object Target extends Applicative.Applyer[Task, Task, Result, mill.api.Ctx] {
@@ -371,57 +422,46 @@ object Target extends Applicative.Applyer[Task, Task, Result, mill.api.Ctx] {
   }
 }
 
-abstract class TargetImplBase[+T](
-    ctx0: mill.define.Ctx,
-    t: Task[T],
-    override val isPrivate: Option[Boolean]
-) extends Target[T] {
-  def evaluate(args: mill.api.Ctx) = args[T](0)
-  val ctx = ctx0.withSegments(segments = ctx0.segments ++ Seq(ctx0.segment))
-  val inputs = Seq(t)
-}
-
 class TargetImpl[+T](
     t: Task[T],
     ctx0: mill.define.Ctx,
     val readWrite: RW[_],
     isPrivate: Option[Boolean]
-) extends TargetImplBase[T](ctx0, t, isPrivate) {
+) extends Target[T](t, ctx0, isPrivate) {
   override def asTarget: Option[Target[T]] = Some(this)
 }
 
+class PersistentImpl[+T](
+    t: Task[T],
+    ctx0: mill.define.Ctx,
+    readWrite: RW[_],
+    isPrivate: Option[Boolean]
+) extends TargetImpl[T](t, ctx0, readWrite, isPrivate) {
+  override def flushDest = false
+}
+
 class Command[+T](
     t: Task[T],
     ctx0: mill.define.Ctx,
     val writer: W[_],
     val cls: Class[_],
     isPrivate: Option[Boolean]
-) extends TargetImplBase[T](ctx0, t, isPrivate) {
+) extends Target[T](t, ctx0, isPrivate) {
   override def asCommand = Some(this)
 }
 
 class WorkerImpl[+T](t: Task[T], ctx0: mill.define.Ctx, isPrivate: Option[Boolean])
-    extends TargetImplBase[T](ctx0, t, isPrivate) {
+  extends Target[T](t, ctx0, isPrivate) {
   override def flushDest = false
   override def asWorker = Some(this)
 }
 
-class PersistentImpl[+T](
-    t: Task[T],
-    ctx0: mill.define.Ctx,
-    readWrite: RW[_],
-    isPrivate: Option[Boolean]
-) extends TargetImpl[T](t, ctx0, readWrite, isPrivate) {
-
-  override def flushDest = false
-}
-
 class InputImpl[T](
     t: Task[T],
     ctx0: mill.define.Ctx,
     val writer: upickle.default.Writer[_],
     isPrivate: Option[Boolean]
-) extends TargetImplBase[T](ctx0, t, isPrivate) {
+) extends Target[T](t, ctx0, isPrivate) {
   override def sideHash = util.Random.nextInt()
 }
 
@@ -440,55 +480,3 @@ class SourceImpl(t: Task[PathRef], ctx0: mill.define.Ctx, isPrivate: Option[Bool
       PathRef.jsonFormatter,
       isPrivate
     )
-
-object Task {
-
-  class Task0[T](t: T) extends Task[T] {
-    lazy val t0 = t
-    val inputs = Nil
-    def evaluate(args: mill.api.Ctx) = t0
-  }
-
-  abstract class Ops[+T] { this: Task[T] =>
-    def map[V](f: T => V) = new Task.Mapped(this, f)
-    def mapDest[V](f: (T, mill.api.Ctx) => Result[V]) = new Task.MappedDest(this, f)
-
-    def filter(f: T => Boolean) = this
-    def withFilter(f: T => Boolean) = this
-    def zip[V](other: Task[V]) = new Task.Zipped(this, other)
-
-  }
-
-  class Sequence[+T](inputs0: Seq[Task[T]]) extends Task[Seq[T]] {
-    val inputs = inputs0
-    def evaluate(args: mill.api.Ctx) = {
-      for (i <- 0 until args.length)
-        yield args(i).asInstanceOf[T]
-    }
-  }
-  class TraverseCtx[+T, V](
-      inputs0: Seq[Task[T]],
-      f: (IndexedSeq[T], mill.api.Ctx) => Result[V]
-  ) extends Task[V] {
-    val inputs = inputs0
-    def evaluate(args: mill.api.Ctx) = {
-      f(
-        for (i <- 0 until args.length)
-          yield args(i).asInstanceOf[T],
-        args
-      )
-    }
-  }
-  class Mapped[+T, +V](source: Task[T], f: T => V) extends Task[V] {
-    def evaluate(args: mill.api.Ctx) = f(args(0))
-    val inputs = List(source)
-  }
-  class MappedDest[+T, +V](source: Task[T], f: (T, mill.api.Ctx) => Result[V]) extends Task[V] {
-    def evaluate(args: mill.api.Ctx) = f(args(0), args)
-    val inputs = List(source)
-  }
-  class Zipped[+T, +V](source1: Task[T], source2: Task[V]) extends Task[(T, V)] {
-    def evaluate(args: mill.api.Ctx) = (args(0), args(1))
-    val inputs = List(source1, source2)
-  }
-}
diff --git a/main/testkit/src/mill/testkit/MillTestkit.scala b/main/testkit/src/mill/testkit/MillTestkit.scala
index a930e816b66..290393eea25 100644
--- a/main/testkit/src/mill/testkit/MillTestkit.scala
+++ b/main/testkit/src/mill/testkit/MillTestkit.scala
@@ -117,7 +117,6 @@ trait MillTestKit {
             evaluated.evaluated.collect {
               case t: TargetImpl[_]
                   if module.millInternal.targets.contains(t)
-                    && !t.isInstanceOf[InputImpl[_]]
                     && !t.ctx.external => t
               case t: mill.define.Command[_] => t
             }.size

From 21ea3252f565aa67490676bfa898ab37fa63d9ca Mon Sep 17 00:00:00 2001
From: Li Haoyi <haoyi.sg@gmail.com>
Date: Mon, 3 Apr 2023 10:44:54 +0800
Subject: [PATCH 11/16] simplify Labelled

---
 main/core/src/mill/define/Task.scala    | 63 +++++++++++++++----------
 main/core/src/mill/eval/Evaluator.scala | 18 ++-----
 2 files changed, 41 insertions(+), 40 deletions(-)

diff --git a/main/core/src/mill/define/Task.scala b/main/core/src/mill/define/Task.scala
index f7b2cc6c44a..70faa999633 100644
--- a/main/core/src/mill/define/Task.scala
+++ b/main/core/src/mill/define/Task.scala
@@ -84,11 +84,10 @@ object Task {
 /**
  * Represents a task that can be referenced by its path segments.
  */
-class Target[+T](
-    t: Task[T],
-    ctx0: mill.define.Ctx,
-    val isPrivate: Option[Boolean]
-) extends Task[T] {
+trait Target[+T] extends Task[T] {
+  def t: Task[T]
+  def ctx0: mill.define.Ctx
+  def isPrivate: Option[Boolean]
   def label: String = ctx.segment match {
     case Segment.Label(v) => v
     case Segment.Cross(_) => throw new IllegalArgumentException(
@@ -101,8 +100,13 @@ class Target[+T](
 
   val ctx = ctx0.withSegments(segments = ctx0.segments ++ Seq(ctx0.segment))
   val inputs = Seq(t)
+
+  def readWriterOpt: Option[upickle.default.ReadWriter[_]] = None
+
+  def writerOpt: Option[upickle.default.Writer[_]] = readWriterOpt.orElse(None)
 }
 
+
 object Target extends Applicative.Applyer[Task, Task, Result, mill.api.Ctx] {
   // convenience
   def dest(implicit ctx: mill.api.Ctx.Dest): os.Path = ctx.dest
@@ -423,60 +427,67 @@ object Target extends Applicative.Applyer[Task, Task, Result, mill.api.Ctx] {
 }
 
 class TargetImpl[+T](
-    t: Task[T],
-    ctx0: mill.define.Ctx,
-    val readWrite: RW[_],
-    isPrivate: Option[Boolean]
-) extends Target[T](t, ctx0, isPrivate) {
+    val t: Task[T],
+    val ctx0: mill.define.Ctx,
+    val readWriter: RW[_],
+    val isPrivate: Option[Boolean]
+) extends Target[T]{
   override def asTarget: Option[Target[T]] = Some(this)
+  override def readWriterOpt = Some(readWriter)
 }
 
 class PersistentImpl[+T](
     t: Task[T],
     ctx0: mill.define.Ctx,
-    readWrite: RW[_],
+    readWriter: RW[_],
     isPrivate: Option[Boolean]
-) extends TargetImpl[T](t, ctx0, readWrite, isPrivate) {
+) extends TargetImpl[T](t, ctx0, readWriter, isPrivate) {
   override def flushDest = false
 }
 
 class Command[+T](
-    t: Task[T],
-    ctx0: mill.define.Ctx,
+    val t: Task[T],
+    val ctx0: mill.define.Ctx,
     val writer: W[_],
     val cls: Class[_],
-    isPrivate: Option[Boolean]
-) extends Target[T](t, ctx0, isPrivate) {
+    val isPrivate: Option[Boolean]
+) extends Target[T] {
   override def asCommand = Some(this)
+  override def writerOpt = Some(writer)
 }
 
-class WorkerImpl[+T](t: Task[T], ctx0: mill.define.Ctx, isPrivate: Option[Boolean])
-  extends Target[T](t, ctx0, isPrivate) {
+class WorkerImpl[+T](val t: Task[T], val ctx0: mill.define.Ctx, val isPrivate: Option[Boolean])
+  extends Target[T]{
   override def flushDest = false
   override def asWorker = Some(this)
 }
 
 class InputImpl[T](
-    t: Task[T],
-    ctx0: mill.define.Ctx,
+    val t: Task[T],
+    val ctx0: mill.define.Ctx,
     val writer: upickle.default.Writer[_],
-    isPrivate: Option[Boolean]
-) extends Target[T](t, ctx0, isPrivate) {
+    val isPrivate: Option[Boolean]
+) extends Target[T]  {
   override def sideHash = util.Random.nextInt()
+  override def writerOpt = Some(writer)
 }
 
 class SourcesImpl(t: Task[Seq[PathRef]], ctx0: mill.define.Ctx, isPrivate: Option[Boolean])
     extends InputImpl[Seq[PathRef]](
       t,
       ctx0,
-      upickle.default.SeqLikeWriter[Seq, PathRef],
+      upickle.default.readwriter[Seq[PathRef]],
       isPrivate
-    )
+    ){
+  override def readWriterOpt = Some(upickle.default.readwriter[Seq[PathRef]])
+}
 
 class SourceImpl(t: Task[PathRef], ctx0: mill.define.Ctx, isPrivate: Option[Boolean])
     extends InputImpl[PathRef](
       t,
       ctx0,
-      PathRef.jsonFormatter,
+      upickle.default.readwriter[PathRef],
       isPrivate
-    )
+    ){
+  override def readWriterOpt = Some(upickle.default.readwriter[PathRef])
+}
diff --git a/main/core/src/mill/eval/Evaluator.scala b/main/core/src/mill/eval/Evaluator.scala
index 2d6a020af6a..2bfd0e2e233 100644
--- a/main/core/src/mill/eval/Evaluator.scala
+++ b/main/core/src/mill/eval/Evaluator.scala
@@ -23,18 +23,7 @@ import scala.jdk.CollectionConverters._
 import scala.reflect.ClassTag
 import scala.util.control.NonFatal
 
-case class Labelled[T](task: Target[T], segments: Segments) {
-  def format: Option[default.ReadWriter[T]] = task match {
-    case t: TargetImpl[T] => Some(t.readWrite.asInstanceOf[upickle.default.ReadWriter[T]])
-    case _ => None
-  }
-  def writer: Option[default.Writer[T]] = task match {
-    case t: mill.define.Command[T] => Some(t.writer.asInstanceOf[upickle.default.Writer[T]])
-    case t: mill.define.InputImpl[T] => Some(t.writer.asInstanceOf[upickle.default.Writer[T]])
-    case t: TargetImpl[T] => Some(t.readWrite.asInstanceOf[upickle.default.ReadWriter[T]])
-    case _ => None
-  }
-}
+case class Labelled[T](task: Target[T], segments: Segments)
 
 /**
  * Evaluate tasks.
@@ -380,7 +369,7 @@ class Evaluator private (_home: os.Path,
               case NonFatal(_) => None
             }
           if cached.inputsHash == inputsHash
-          reader <- labelledNamedTask.format
+          reader <- labelledNamedTask.task.readWriterOpt
           parsed <-
             try Some(upickle.default.read(cached.value)(reader))
             catch {
@@ -493,7 +482,8 @@ class Evaluator private (_home: os.Path,
         }
       case None =>
         val terminalResult = labelledNamedTask
-          .writer
+          .task
+          .writerOpt
           .asInstanceOf[Option[upickle.default.Writer[Any]]]
           .map(w => upickle.default.writeJs(v)(w) -> v)
 

From 905011bf81b57c8cea7045fce8b182f2244861f5 Mon Sep 17 00:00:00 2001
From: Li Haoyi <haoyi.sg@gmail.com>
Date: Mon, 3 Apr 2023 11:06:59 +0800
Subject: [PATCH 12/16] privatize

---
 main/core/src/mill/define/Discover.scala | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/main/core/src/mill/define/Discover.scala b/main/core/src/mill/define/Discover.scala
index 5d221c0676d..c7cc67e4abd 100644
--- a/main/core/src/mill/define/Discover.scala
+++ b/main/core/src/mill/define/Discover.scala
@@ -29,7 +29,7 @@ object Discover {
   private def unapply[T](discover: Discover[T])
       : Option[Map[Class[_], Seq[(Int, mainargs.MainData[_, _])]]] = Some(discover.value)
 
-  class Router(val ctx: blackbox.Context) extends mainargs.Macros(ctx) {
+  private class Router(val ctx: blackbox.Context) extends mainargs.Macros(ctx) {
     import c.universe._
 
     def applyImpl[T: WeakTypeTag]: Expr[Discover[T]] = {

From e8902a715681e73d3b205f90bee5f7e75a1e018e Mon Sep 17 00:00:00 2001
From: Li Haoyi <haoyi.sg@gmail.com>
Date: Mon, 3 Apr 2023 11:21:16 +0800
Subject: [PATCH 13/16] resurrect NamedTask

---
 main/core/src/mill/define/Task.scala          | 27 ++++++++++---------
 main/core/src/mill/define/package.scala       |  1 -
 main/core/src/mill/eval/Evaluator.scala       | 12 ++++-----
 main/core/src/mill/eval/EvaluatorPaths.scala  |  4 +--
 .../mill/eval/EvaluatorPathsResolver.scala    |  4 +--
 .../mill/main/graphviz/GraphvizTools.scala    |  8 +++---
 main/src/mill/main/MainModule.scala           | 14 +++++-----
 main/src/mill/main/Resolve.scala              |  2 +-
 main/src/mill/main/ResolveMetadata.scala      |  2 +-
 main/src/mill/main/ResolveTasks.scala         | 12 ++++-----
 main/src/mill/main/RunScript.scala            |  2 +-
 main/src/mill/main/TokenReaders.scala         |  4 +--
 main/test/src/mill/define/GraphTests.scala    |  2 +-
 .../src/mill/eval/JavaCompileJarTests.scala   |  4 ---
 main/test/src/mill/main/MainTests.scala       |  6 ++---
 .../mill/scalajslib/HelloJSWorldTests.scala   |  2 +-
 .../src/mill/scalalib/HelloWorldTests.scala   | 18 ++++++-------
 .../HelloNativeWorldTests.scala               |  2 +-
 18 files changed, 61 insertions(+), 65 deletions(-)

diff --git a/main/core/src/mill/define/Task.scala b/main/core/src/mill/define/Task.scala
index 70faa999633..9abe5fcd247 100644
--- a/main/core/src/mill/define/Task.scala
+++ b/main/core/src/mill/define/Task.scala
@@ -36,7 +36,7 @@ abstract class Task[+T] extends Task.Ops[T] with Applyable[Task, T] {
 
   def asTarget: Option[Target[T]] = None
   def asCommand: Option[Command[T]] = None
-  def asWorker: Option[Target[T]] = None
+  def asWorker: Option[Worker[T]] = None
   def self: Task[T] = this
 }
 
@@ -84,7 +84,7 @@ object Task {
 /**
  * Represents a task that can be referenced by its path segments.
  */
-trait Target[+T] extends Task[T] {
+trait NamedTask[+T] extends Task[T] {
   def t: Task[T]
   def ctx0: mill.define.Ctx
   def isPrivate: Option[Boolean]
@@ -106,6 +106,7 @@ trait Target[+T] extends Task[T] {
   def writerOpt: Option[upickle.default.Writer[_]] = readWriterOpt.orElse(None)
 }
 
+trait Target[+T] extends NamedTask[T]
 
 object Target extends Applicative.Applyer[Task, Task, Result, mill.api.Ctx] {
   // convenience
@@ -358,31 +359,31 @@ object Target extends Applicative.Applyer[Task, Task, Result, mill.api.Ctx] {
     )
   }
 
-  def worker[T](t: Task[T])(implicit ctx: mill.define.Ctx): Target[T] = macro workerImpl1[T]
+  def worker[T](t: Task[T])(implicit ctx: mill.define.Ctx): Worker[T] = macro workerImpl1[T]
 
   def workerImpl1[T: c.WeakTypeTag](c: Context)(t: c.Expr[Task[T]])(ctx: c.Expr[mill.define.Ctx])
-      : c.Expr[Target[T]] = {
+      : c.Expr[Worker[T]] = {
     import c.universe._
 
     val taskIsPrivate = isPrivateTargetOption(c)
 
-    mill.moduledefs.Cacher.impl0[Target[T]](c)(
+    mill.moduledefs.Cacher.impl0[Worker[T]](c)(
       reify(
-        new WorkerImpl[T](t.splice, ctx.splice, taskIsPrivate.splice)
+        new Worker[T](t.splice, ctx.splice, taskIsPrivate.splice)
       )
     )
   }
-  def worker[T](t: Result[T])(implicit ctx: mill.define.Ctx): Target[T] = macro workerImpl2[T]
+  def worker[T](t: Result[T])(implicit ctx: mill.define.Ctx): Worker[T] = macro workerImpl2[T]
 
   def workerImpl2[T: c.WeakTypeTag](c: Context)(t: c.Expr[T])(ctx: c.Expr[mill.define.Ctx])
-      : c.Expr[Target[T]] = {
+      : c.Expr[Worker[T]] = {
     import c.universe._
 
     val taskIsPrivate = isPrivateTargetOption(c)
 
-    mill.moduledefs.Cacher.impl0[Target[T]](c)(
+    mill.moduledefs.Cacher.impl0[Worker[T]](c)(
       reify(
-        new WorkerImpl[T](
+        new Worker[T](
           Applicative.impl[Task, T, mill.api.Ctx](c)(t).splice,
           ctx.splice,
           taskIsPrivate.splice
@@ -451,13 +452,13 @@ class Command[+T](
     val writer: W[_],
     val cls: Class[_],
     val isPrivate: Option[Boolean]
-) extends Target[T] {
+) extends NamedTask[T] {
   override def asCommand = Some(this)
   override def writerOpt = Some(writer)
 }
 
-class WorkerImpl[+T](val t: Task[T], val ctx0: mill.define.Ctx, val isPrivate: Option[Boolean])
-  extends Target[T]{
+class Worker[+T](val t: Task[T], val ctx0: mill.define.Ctx, val isPrivate: Option[Boolean])
+  extends NamedTask[T]{
   override def flushDest = false
   override def asWorker = Some(this)
 }
diff --git a/main/core/src/mill/define/package.scala b/main/core/src/mill/define/package.scala
index 6cb8c145dc9..23f2fb6ad34 100644
--- a/main/core/src/mill/define/package.scala
+++ b/main/core/src/mill/define/package.scala
@@ -4,5 +4,4 @@ package object define{
   type Sources = define.Target[Seq[mill.api.PathRef]]
   type Input[T] = define.Target[T]
   type Persistent[T] = define.Target[T]
-  type Worker[T] = define.Target[T]
 }
diff --git a/main/core/src/mill/eval/Evaluator.scala b/main/core/src/mill/eval/Evaluator.scala
index 2bfd0e2e233..0e12f30c015 100644
--- a/main/core/src/mill/eval/Evaluator.scala
+++ b/main/core/src/mill/eval/Evaluator.scala
@@ -23,7 +23,7 @@ import scala.jdk.CollectionConverters._
 import scala.reflect.ClassTag
 import scala.util.control.NonFatal
 
-case class Labelled[T](task: Target[T], segments: Segments)
+case class Labelled[T](task: NamedTask[T], segments: Segments)
 
 /**
  * Evaluate tasks.
@@ -318,7 +318,7 @@ class Evaluator private (_home: os.Path,
     val scriptsHash = {
       val scripts = new Loose.Agg.Mutable[os.Path]()
       group.iterator.flatMap(t => Iterator(t) ++ t.inputs).foreach {
-        case namedTask: Target[_] => scripts.append(os.Path(namedTask.ctx.fileName))
+        case namedTask: NamedTask[_] => scripts.append(os.Path(namedTask.ctx.fileName))
         case _ =>
       }
 
@@ -605,7 +605,7 @@ class Evaluator private (_home: os.Path,
       newResults(task) = for (v <- res) yield {
         (
           v,
-          if (task.isInstanceOf[WorkerImpl[_]]) inputsHash
+          if (task.isInstanceOf[Worker[_]]) inputsHash
           else v.##
         )
       }
@@ -811,10 +811,10 @@ object Evaluator {
     val seen = collection.mutable.Set.empty[Segments]
     val overridden = collection.mutable.Set.empty[Task[_]]
     topoSorted.values.reverse.iterator.foreach {
-      case x: Target[_] if x.isPrivate == Some(true) =>
+      case x: NamedTask[_] if x.isPrivate == Some(true) =>
         // we always need to store them in the super-path
         overridden.add(x)
-      case x: Target[_] =>
+      case x: NamedTask[_] =>
         if (!seen.contains(x.ctx.segments)) seen.add(x.ctx.segments)
         else overridden.add(x)
       case _ => // donothing
@@ -822,7 +822,7 @@ object Evaluator {
 
     val sortedGroups = Graph.groupAroundImportantTargets(topoSorted) {
       // important: all named tasks and those explicitly requested
-      case t: Target[Any] =>
+      case t: NamedTask[Any] =>
         val segments = t.ctx.segments
         Right(
           Labelled(
diff --git a/main/core/src/mill/eval/EvaluatorPaths.scala b/main/core/src/mill/eval/EvaluatorPaths.scala
index d8392485815..04f22cc6b8a 100644
--- a/main/core/src/mill/eval/EvaluatorPaths.scala
+++ b/main/core/src/mill/eval/EvaluatorPaths.scala
@@ -1,7 +1,7 @@
 package mill.eval
 
 import mill.api.internal
-import mill.define.{Target, Segment, Segments}
+import mill.define.{NamedTask, Segment, Segments, Target}
 
 case class EvaluatorPaths private (dest: os.Path, meta: os.Path, log: os.Path) {
   private def copy(dest: os.Path = dest, meta: os.Path = meta, log: os.Path = log): EvaluatorPaths =
@@ -37,6 +37,6 @@ object EvaluatorPaths {
   }
   def resolveDestPaths(
       workspacePath: os.Path,
-      task: Target[_]
+      task: NamedTask[_]
   ): EvaluatorPaths = resolveDestPaths(workspacePath, task.ctx.segments, task.ctx.foreign)
 }
diff --git a/main/core/src/mill/eval/EvaluatorPathsResolver.scala b/main/core/src/mill/eval/EvaluatorPathsResolver.scala
index 1843c311a03..f7d0ad31907 100644
--- a/main/core/src/mill/eval/EvaluatorPathsResolver.scala
+++ b/main/core/src/mill/eval/EvaluatorPathsResolver.scala
@@ -1,9 +1,9 @@
 package mill.eval
 
-import mill.define.{Target, Segments}
+import mill.define.{NamedTask, Segments}
 
 trait EvaluatorPathsResolver {
-  def resolveDest(task: Target[_]): EvaluatorPaths =
+  def resolveDest(task: NamedTask[_]): EvaluatorPaths =
     resolveDest(task.ctx.segments, task.ctx.foreign)
   def resolveDest(segments: Segments, foreignSegments: Option[Segments] = None): EvaluatorPaths
 }
diff --git a/main/graphviz/src/mill/main/graphviz/GraphvizTools.scala b/main/graphviz/src/mill/main/graphviz/GraphvizTools.scala
index f830f3d8f66..007b0c6bc48 100644
--- a/main/graphviz/src/mill/main/graphviz/GraphvizTools.scala
+++ b/main/graphviz/src/mill/main/graphviz/GraphvizTools.scala
@@ -1,14 +1,14 @@
 package mill.main.graphviz
 import guru.nidi.graphviz.attribute.Style
-import mill.define.{Graph, Target}
+import mill.define.{Graph, NamedTask}
 import org.jgrapht.graph.{DefaultEdge, SimpleDirectedGraph}
 object GraphvizTools {
-  def apply(targets: Seq[Target[Any]], rs: Seq[Target[Any]], dest: os.Path) = {
+  def apply(targets: Seq[NamedTask[Any]], rs: Seq[NamedTask[Any]], dest: os.Path) = {
     val transitive = Graph.transitiveTargets(rs.distinct)
     val topoSorted = Graph.topoSorted(transitive)
     val goalSet = rs.toSet
     val sortedGroups = Graph.groupAroundImportantTargets(topoSorted) {
-      case x: Target[Any] if goalSet.contains(x) => x
+      case x: NamedTask[Any] if goalSet.contains(x) => x
     }
     import guru.nidi.graphviz.engine.{Format, Graphviz}
     import guru.nidi.graphviz.model.Factory._
@@ -19,7 +19,7 @@ object GraphvizTools {
           k,
           for {
             v <- vs.items
-            dest <- v.inputs.collect { case v: Target[Any] => v }
+            dest <- v.inputs.collect { case v: NamedTask[Any] => v }
             if goalSet.contains(dest)
           } yield dest
         )
diff --git a/main/src/mill/main/MainModule.scala b/main/src/mill/main/MainModule.scala
index eef28cc3f2a..d59caeb32b4 100644
--- a/main/src/mill/main/MainModule.scala
+++ b/main/src/mill/main/MainModule.scala
@@ -5,7 +5,7 @@ import mainargs.TokensReader
 import java.util.concurrent.LinkedBlockingQueue
 import mill.{BuildInfo, T}
 import mill.api.{Ctx, PathRef, Result, internal}
-import mill.define.{Command, Segments, SelectMode, Target, TargetImpl, Task}
+import mill.define.{Command, Segments, SelectMode, NamedTask, TargetImpl, Task}
 import mill.eval.{Evaluator, EvaluatorPaths}
 import mill.util.{PrintLogger, Watched}
 import pprint.{Renderer, Tree, Truncated}
@@ -20,7 +20,7 @@ object MainModule {
       evaluator: Evaluator,
       targets: Seq[String],
       selectMode: SelectMode
-  )(f: List[Target[Any]] => T): Result[T] = {
+  )(f: List[NamedTask[Any]] => T): Result[T] = {
     RunScript.resolveTasks(mill.main.ResolveTasks, evaluator, targets, selectMode) match {
       case Left(err) => Result.Failure(err)
       case Right(tasks) => Result.Success(f(tasks))
@@ -155,7 +155,7 @@ trait MainModule extends mill.Module {
             Result.Failure(s"No path found between $src and $dest")
           case Some(list) =>
             val labels = list
-              .collect { case n: Target[_] => n.ctx.segments.render }
+              .collect { case n: NamedTask[_] => n.ctx.segments.render }
 
             labels.foreach(mill.T.log.outputStream.println(_))
 
@@ -174,7 +174,7 @@ trait MainModule extends mill.Module {
         resolveParents
       )
     }
-    def pprintTask(t: Target[_], evaluator: Evaluator): Tree.Lazy = {
+    def pprintTask(t: NamedTask[_], evaluator: Evaluator): Tree.Lazy = {
       val seen = mutable.Set.empty[Task[_]]
 
       def rec(t: Task[_]): Seq[Segments] = {
@@ -399,11 +399,11 @@ trait MainModule extends mill.Module {
       targets: Seq[String],
       ctx: Ctx,
       vizWorker: VizWorker,
-      planTasks: Option[List[Target[_]]] = None
+      planTasks: Option[List[NamedTask[_]]] = None
   ): Result[Seq[PathRef]] = {
     def callVisualizeModule(
-        rs: List[Target[Any]],
-        allRs: List[Target[Any]]
+        rs: List[NamedTask[Any]],
+        allRs: List[NamedTask[Any]]
     ): Result[Seq[PathRef]] = {
       val (in, out) = vizWorker
       in.put((rs, allRs, ctx.dest))
diff --git a/main/src/mill/main/Resolve.scala b/main/src/mill/main/Resolve.scala
index 5cbe181b2c6..940f0eba62a 100644
--- a/main/src/mill/main/Resolve.scala
+++ b/main/src/mill/main/Resolve.scala
@@ -244,7 +244,7 @@ abstract class Resolve[R: ClassTag] {
               }
             ).map(
               _.distinctBy {
-                case t: Target[_] => t.ctx.segments
+                case t: NamedTask[_] => t.ctx.segments
                 case t => t
               }
             )
diff --git a/main/src/mill/main/ResolveMetadata.scala b/main/src/mill/main/ResolveMetadata.scala
index b72521844f2..43fa1fded21 100644
--- a/main/src/mill/main/ResolveMetadata.scala
+++ b/main/src/mill/main/ResolveMetadata.scala
@@ -8,7 +8,7 @@ object ResolveMetadata extends Resolve[String] {
     val targets =
       obj
         .millInternal
-        .reflectAll[Target[_]]
+        .reflectAll[NamedTask[_]]
         .map(_.toString)
     val commands =
       for {
diff --git a/main/src/mill/main/ResolveTasks.scala b/main/src/mill/main/ResolveTasks.scala
index 6b4d3e1896a..28b4a2e88ca 100644
--- a/main/src/mill/main/ResolveTasks.scala
+++ b/main/src/mill/main/ResolveTasks.scala
@@ -3,14 +3,14 @@ package mill.main
 import mill.define._
 import mill.main.ResolveMetadata.singleModuleMeta
 
-object ResolveTasks extends Resolve[Target[Any]] {
+object ResolveTasks extends Resolve[NamedTask[Any]] {
 
   def endResolveCross(
       obj: Module,
       last: List[String],
       discover: Discover[_],
       rest: Seq[String]
-  ): Either[String, Seq[Target[Any]]] = {
+  ): Either[String, Seq[NamedTask[Any]]] = {
     obj match {
       case _: Cross[Module] =>
         Resolve.runDefault(obj, Segment.Cross(last), discover, rest).flatten.headOption match {
@@ -34,20 +34,20 @@ object ResolveTasks extends Resolve[Target[Any]] {
       last: String,
       discover: Discover[_],
       rest: Seq[String]
-  ): Either[String, Seq[Target[Any]]] = last match {
+  ): Either[String, Seq[NamedTask[Any]]] = last match {
     case "__" =>
       Right(
         obj.millInternal.modules
           .filter(_ != obj)
-          .flatMap(m => m.millInternal.reflectAll[Target[_]])
+          .flatMap(m => m.millInternal.reflectAll[NamedTask[_]])
       )
-    case "_" => Right(obj.millInternal.reflectAll[Target[_]])
+    case "_" => Right(obj.millInternal.reflectAll[NamedTask[_]])
 
     case _ =>
       val target =
         obj
           .millInternal
-          .reflectSingle[Target[_]](last)
+          .reflectSingle[NamedTask[_]](last)
           .map(Right(_))
 
       val command = Resolve.invokeCommand(
diff --git a/main/src/mill/main/RunScript.scala b/main/src/mill/main/RunScript.scala
index e8e198fc8ff..07a12dd8f4f 100644
--- a/main/src/mill/main/RunScript.scala
+++ b/main/src/mill/main/RunScript.scala
@@ -181,7 +181,7 @@ object RunScript {
       case 0 =>
         val nameAndJson = for (t <- targets.toSeq) yield {
           t match {
-            case t: mill.define.Target[_] =>
+            case t: mill.define.NamedTask[_] =>
               val jsonFile = EvaluatorPaths.resolveDestPaths(evaluator.outPath, t).meta
               val metadata = upickle.default.read[Evaluator.Cached](ujson.read(jsonFile.toIO))
               Some(t.toString, metadata.value)
diff --git a/main/src/mill/main/TokenReaders.scala b/main/src/mill/main/TokenReaders.scala
index 1ef796f183d..42c4eff001d 100644
--- a/main/src/mill/main/TokenReaders.scala
+++ b/main/src/mill/main/TokenReaders.scala
@@ -4,7 +4,7 @@ import mainargs.TokensReader
 import mill.eval.Evaluator
 import mill.define.{SelectMode, Target, Task}
 
-case class Tasks[T](value: Seq[mill.define.Target[T]])
+case class Tasks[T](value: Seq[mill.define.NamedTask[T]])
 
 object Tasks {
   class TokenReader[T]()
@@ -16,7 +16,7 @@ object Tasks {
             Evaluator.currentEvaluator.get,
             s,
             SelectMode.Single
-          ).map(x => Tasks(x.asInstanceOf[Seq[mill.define.Target[T]]])),
+          ).map(x => Tasks(x.asInstanceOf[Seq[mill.define.NamedTask[T]]])),
         alwaysRepeatable = false,
         allowEmpty = false
       )
diff --git a/main/test/src/mill/define/GraphTests.scala b/main/test/src/mill/define/GraphTests.scala
index a298f5e4a0a..36c5230d4c1 100644
--- a/main/test/src/mill/define/GraphTests.scala
+++ b/main/test/src/mill/define/GraphTests.scala
@@ -168,7 +168,7 @@ object GraphTests extends TestSuite {
           Graph.transitiveTargets(Agg.from(goals))
         )
         val grouped = Graph.groupAroundImportantTargets(topoSorted) {
-          case t: Target[Any] => t
+          case t: NamedTask[Any] => t
           case t if goals.contains(t) => t
         }
         grouped.keyCount
diff --git a/main/test/src/mill/eval/JavaCompileJarTests.scala b/main/test/src/mill/eval/JavaCompileJarTests.scala
index 765474d0608..9839929413a 100644
--- a/main/test/src/mill/eval/JavaCompileJarTests.scala
+++ b/main/test/src/mill/eval/JavaCompileJarTests.scala
@@ -72,15 +72,11 @@ object JavaCompileJarTests extends TestSuite {
 
       def append(path: os.Path, txt: String) = os.write.append(path, txt)
 
-      println("=" * 150)
-
       check(
         targets = Agg(jar),
         expected = Agg(allSources, classFiles, jar)
       )
 
-      println("=" * 150)
-
       // Re-running with no changes results in nothing being evaluated
       check(targets = Agg(jar), expected = Agg())
       // Appending an empty string gets ignored due to file-content hashing
diff --git a/main/test/src/mill/main/MainTests.scala b/main/test/src/mill/main/MainTests.scala
index 0516104887f..2fdf22ec688 100644
--- a/main/test/src/mill/main/MainTests.scala
+++ b/main/test/src/mill/main/MainTests.scala
@@ -1,18 +1,18 @@
 package mill.main
 
-import mill.define.{Target, Segment, SelectMode}
+import mill.define.{NamedTask, Segment, SelectMode}
 import mill.util.TestGraphs._
 import utest._
 object MainTests extends TestSuite {
 
   def check[T <: mill.define.BaseModule](module: T)(
       selectorString: String,
-      expected0: Either[String, Seq[T => Target[_]]]
+      expected0: Either[String, Seq[T => NamedTask[_]]]
   ) = checkSeq(module)(Seq(selectorString), expected0)
 
   def checkSeq[T <: mill.define.BaseModule](module: T)(
       selectorStrings: Seq[String],
-      expected0: Either[String, Seq[T => Target[_]]]
+      expected0: Either[String, Seq[T => NamedTask[_]]]
   ) = {
 
     val expected = expected0.map(_.map(_(module)))
diff --git a/scalajslib/test/src/mill/scalajslib/HelloJSWorldTests.scala b/scalajslib/test/src/mill/scalajslib/HelloJSWorldTests.scala
index 92b90f80e0d..3f797a7b867 100644
--- a/scalajslib/test/src/mill/scalajslib/HelloJSWorldTests.scala
+++ b/scalajslib/test/src/mill/scalajslib/HelloJSWorldTests.scala
@@ -199,7 +199,7 @@ object HelloJSWorldTests extends TestSuite {
       }
     }
 
-    def runTests(testTask: define.Target[(String, Seq[TestRunner.Result])])
+    def runTests(testTask: define.NamedTask[(String, Seq[TestRunner.Result])])
         : Map[String, Map[String, TestRunner.Result]] = {
       val Left(Result.Failure(_, Some(res))) = helloWorldEvaluator(testTask)
 
diff --git a/scalalib/test/src/mill/scalalib/HelloWorldTests.scala b/scalalib/test/src/mill/scalalib/HelloWorldTests.scala
index fcbb19db54a..c37bfb4cb8d 100644
--- a/scalalib/test/src/mill/scalalib/HelloWorldTests.scala
+++ b/scalalib/test/src/mill/scalalib/HelloWorldTests.scala
@@ -7,7 +7,7 @@ import scala.util.{Properties, Using}
 import scala.xml.NodeSeq
 import mill._
 import mill.api.Result
-import mill.define.{Input, Target}
+import mill.define.{Input, NamedTask, Target}
 import mill.eval.{Evaluator, EvaluatorPaths}
 import mill.modules.Assembly
 import mill.scalalib.publish.{VersionControl, _}
@@ -1225,13 +1225,13 @@ object HelloWorldTests extends TestSuite {
             // we reconstruct faulty behavior
             val Right((result, _)) = eval.apply(t)
             assert(
-              result.path.last == (t.asInstanceOf[Target[_]].label + ".dest"),
+              result.path.last == (t.asInstanceOf[NamedTask[_]].label + ".dest"),
               os.exists(result.path)
             )
             os.remove.all(result.path)
             val Right((result2, _)) = eval.apply(t)
             assert(
-              result2.path.last == (t.asInstanceOf[Target[_]].label + ".dest"),
+              result2.path.last == (t.asInstanceOf[NamedTask[_]].label + ".dest"),
               // as the result was cached but not checked, this path is missing
               os.exists(result2.path) == flip
             )
@@ -1244,13 +1244,13 @@ object HelloWorldTests extends TestSuite {
           // we reconstruct faulty behavior
           val Right((result, _)) = eval.apply(t)
           assert(
-            result.map(_.path.last) == Seq(t.asInstanceOf[Target[_]].label + ".dest"),
+            result.map(_.path.last) == Seq(t.asInstanceOf[NamedTask[_]].label + ".dest"),
             result.forall(p => os.exists(p.path))
           )
           result.foreach(p => os.remove.all(p.path))
           val Right((result2, _)) = eval.apply(t)
           assert(
-            result2.map(_.path.last) == Seq(t.asInstanceOf[Target[_]].label + ".dest"),
+            result2.map(_.path.last) == Seq(t.asInstanceOf[NamedTask[_]].label + ".dest"),
             // as the result was cached but not checked, this path is missing
             result2.forall(p => os.exists(p.path) == flip)
           )
@@ -1263,13 +1263,13 @@ object HelloWorldTests extends TestSuite {
           // we reconstruct faulty behavior
           val Right((result, _)) = eval.apply(t)
           assert(
-            result.map(_.path.last) == Agg(t.asInstanceOf[Target[_]].label + ".dest"),
+            result.map(_.path.last) == Agg(t.asInstanceOf[NamedTask[_]].label + ".dest"),
             result.forall(p => os.exists(p.path))
           )
           result.foreach(p => os.remove.all(p.path))
           val Right((result2, _)) = eval.apply(t)
           assert(
-            result2.map(_.path.last) == Agg(t.asInstanceOf[Target[_]].label + ".dest"),
+            result2.map(_.path.last) == Agg(t.asInstanceOf[NamedTask[_]].label + ".dest"),
             // as the result was cached but not checked, this path is missing
             result2.forall(p => os.exists(p.path) == flip)
           )
@@ -1283,13 +1283,13 @@ object HelloWorldTests extends TestSuite {
             // we reconstruct faulty behavior
             val Right((result, _)) = eval.apply(t)
             assert(
-              result._1.path.last == (t.asInstanceOf[Target[_]].label + ".dest"),
+              result._1.path.last == (t.asInstanceOf[NamedTask[_]].label + ".dest"),
               os.exists(result._1.path)
             )
             os.remove.all(result._1.path)
             val Right((result2, _)) = eval.apply(t)
             assert(
-              result2._1.path.last == (t.asInstanceOf[Target[_]].label + ".dest"),
+              result2._1.path.last == (t.asInstanceOf[NamedTask[_]].label + ".dest"),
               // as the result was cached but not checked, this path is missing
               os.exists(result2._1.path) == flip
             )
diff --git a/scalanativelib/test/src/mill/scalanativelib/HelloNativeWorldTests.scala b/scalanativelib/test/src/mill/scalanativelib/HelloNativeWorldTests.scala
index 1d399df8c8a..480ddecdfc4 100644
--- a/scalanativelib/test/src/mill/scalanativelib/HelloNativeWorldTests.scala
+++ b/scalanativelib/test/src/mill/scalanativelib/HelloNativeWorldTests.scala
@@ -154,7 +154,7 @@ object HelloNativeWorldTests extends TestSuite {
       )
     }
 
-    def runTests(testTask: define.Target[(String, Seq[TestRunner.Result])])
+    def runTests(testTask: define.NamedTask[(String, Seq[TestRunner.Result])])
         : Map[String, Map[String, TestRunner.Result]] = {
       val Left(Result.Failure(_, Some(res))) = helloWorldEvaluator(testTask)
 

From 3fbb31595823f8a285f6228725335d96b4bdd778 Mon Sep 17 00:00:00 2001
From: Li Haoyi <haoyi.sg@gmail.com>
Date: Mon, 3 Apr 2023 11:21:43 +0800
Subject: [PATCH 14/16] .

---
 main/core/src/mill/define/Task.scala | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/main/core/src/mill/define/Task.scala b/main/core/src/mill/define/Task.scala
index 9abe5fcd247..94e755a25db 100644
--- a/main/core/src/mill/define/Task.scala
+++ b/main/core/src/mill/define/Task.scala
@@ -91,7 +91,7 @@ trait NamedTask[+T] extends Task[T] {
   def label: String = ctx.segment match {
     case Segment.Label(v) => v
     case Segment.Cross(_) => throw new IllegalArgumentException(
-        "Target only support a ctx with a Label segment, but found a Cross."
+        "NamedTask only support a ctx with a Label segment, but found a Cross."
       )
   }
   override def toString = ctx.segments.render

From 33a87a63602e6f4095b05843156f6580e6dba129 Mon Sep 17 00:00:00 2001
From: Li Haoyi <haoyi.sg@gmail.com>
Date: Mon, 3 Apr 2023 11:23:34 +0800
Subject: [PATCH 15/16] .

---
 main/test/src/mill/define/DiscoverTests.scala   | 2 +-
 main/test/src/mill/define/MacroErrorTests.scala | 2 --
 main/testkit/src/mill/testkit/MillTestkit.scala | 6 +++---
 3 files changed, 4 insertions(+), 6 deletions(-)

diff --git a/main/test/src/mill/define/DiscoverTests.scala b/main/test/src/mill/define/DiscoverTests.scala
index 128d0dffd26..a08281c2db7 100644
--- a/main/test/src/mill/define/DiscoverTests.scala
+++ b/main/test/src/mill/define/DiscoverTests.scala
@@ -7,7 +7,7 @@ object DiscoverTests extends TestSuite {
   val testGraphs = new TestGraphs
   val tests = Tests {
     def check[T <: Module](m: T)(targets: (T => Target[_])*) = {
-      val discovered = m.millInternal.targets.filter(_.asCommand.isEmpty)
+      val discovered = m.millInternal.targets
       val expected = targets.map(_(m)).toSet
       assert(discovered == expected)
     }
diff --git a/main/test/src/mill/define/MacroErrorTests.scala b/main/test/src/mill/define/MacroErrorTests.scala
index 9ec8e7fad5b..908e9853509 100644
--- a/main/test/src/mill/define/MacroErrorTests.scala
+++ b/main/test/src/mill/define/MacroErrorTests.scala
@@ -29,8 +29,6 @@ object MacroErrorTests extends TestSuite {
         )
       }
 
-      // WIP getting this error reporting working again
-
       "target" - {
         val e = compileError("""
           object foo extends mill.util.TestUtil.BaseModule{
diff --git a/main/testkit/src/mill/testkit/MillTestkit.scala b/main/testkit/src/mill/testkit/MillTestkit.scala
index 290393eea25..7f4a8274f32 100644
--- a/main/testkit/src/mill/testkit/MillTestkit.scala
+++ b/main/testkit/src/mill/testkit/MillTestkit.scala
@@ -147,11 +147,11 @@ trait MillTestKit {
     }
 
     def check(targets: Agg[Task[_]], expected: Agg[Task[_]]): Unit = {
-      val targets2 = evaluator.evaluate(targets)
+
+
+      val evaluated = evaluator.evaluate(targets)
         .evaluated
         .flatMap(_.asTarget)
-
-      val evaluated = targets2
         .filter(module.millInternal.targets.contains)
         .filter(!_.isInstanceOf[InputImpl[_]])
       assert(

From dcb7d9fb0b5ba48d6b35ac354008e7ef6b6602fa Mon Sep 17 00:00:00 2001
From: Li Haoyi <haoyi.sg@gmail.com>
Date: Mon, 3 Apr 2023 12:37:03 +0800
Subject: [PATCH 16/16] .

---
 example/web/4-webapp-scalajs/build.sc        | 2 +-
 example/web/5-webapp-scalajs-shared/build.sc | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/example/web/4-webapp-scalajs/build.sc b/example/web/4-webapp-scalajs/build.sc
index 6f3d826a7fd..1d923ac2492 100644
--- a/example/web/4-webapp-scalajs/build.sc
+++ b/example/web/4-webapp-scalajs/build.sc
@@ -8,7 +8,7 @@ object app extends RootModule with ScalaModule{
     ivy"com.lihaoyi::scalatags:0.12.0"
   )
 
-  def resources = T.sources{
+  def resources = T{
     os.makeDir(T.dest / "webapp")
     val jsPath = client.fastLinkJS().dest.path
     // Move the main.js[.map] files into the proper filesystem position
diff --git a/example/web/5-webapp-scalajs-shared/build.sc b/example/web/5-webapp-scalajs-shared/build.sc
index a6ef830533f..581d4afb613 100644
--- a/example/web/5-webapp-scalajs-shared/build.sc
+++ b/example/web/5-webapp-scalajs-shared/build.sc
@@ -14,7 +14,7 @@ object app extends RootModule with AppScalaModule{
 
   def ivyDeps = Agg(ivy"com.lihaoyi::cask:0.9.0")
 
-  def resources = T.sources{
+  def resources = T{
     os.makeDir(T.dest / "webapp")
     val jsPath = client.fastLinkJS().dest.path
     os.copy(jsPath / "main.js", T.dest / "webapp" / "main.js")