.

main/src/mill/main/RootModule.scala

@@ -20,6 +20,14 @@ abstract class RootModule(implicit
     ctx: mill.define.Ctx
 ) extends RootModule.Base(foreign0 = ctx.foreign)
 
+abstract class RootModuleForeign(implicit
+    baseModuleInfo: RootModule.Info,
+    millModuleEnclosing0: sourcecode.Enclosing,
+    millModuleLine0: sourcecode.Line,
+    millFile0: sourcecode.File,
+    ctx: mill.define.Ctx
+) extends RootModule.Foreign(foreign0 = ctx.foreign)
+
 @internal
 object RootModule {
   abstract class Base(foreign0: Option[Segments] = None)(implicit

main/src/mill/package.scala

@@ -10,8 +10,7 @@ package object mill extends mill.api.JsonFormatters {
   val Cross = define.Cross
   type Agg[T] = mill.api.Loose.Agg[T]
   val Agg = mill.api.Loose.Agg
-  type RootModule = mill.main.RootModule
-  val RootModule = mill.main.RootModule
+
   class root extends scala.annotation.StaticAnnotation
   type Args = define.Args
   val Args = define.Args

runner/src/mill/runner/MillBuildRootModule.scala

@@ -10,7 +10,7 @@ import mill.util.Util.millProjectModule
 import mill.scalalib.api.Versions
 import pprint.Util.literalize
 import FileImportGraph.backtickWrap
-import mill.main.BuildInfo
+import mill.main.{BuildInfo, RootModule}
 
 import scala.collection.immutable.SortedMap
 import scala.util.Try
@@ -354,6 +354,10 @@ object MillBuildRootModule {
         s"_root_.mill.main.RootModule.Foreign(Some(_root_.mill.define.Segments.labels($segsList)))"
       }
 
+    val imports =
+      if (name == "build") "import mill.main.RootModule"
+      else "import mill.main.{RootModuleForeign => RootModule}"
+
     val miscInfoName = s"MiscInfo_$name"
 
     val pkgLine = pkg.map(p => "package " + backtickWrap(p)).mkString("\n")
@@ -362,6 +366,7 @@ object MillBuildRootModule {
       s"""$pkgLine
          |
          |import _root_.mill.runner.MillBuildRootModule
+         |$imports
          |
          |object ${backtickWrap(miscInfoName)} {
          |  implicit lazy val millBuildRootModuleInfo: _root_.mill.runner.MillBuildRootModule.Info = _root_.mill.runner.MillBuildRootModule.Info(