diff --git a/hail/build.mill b/hail/build.mill
index a56dddbf5296..c65a1efd3d69 100644
--- a/hail/build.mill
+++ b/hail/build.mill
@@ -72,7 +72,7 @@ object Deps {
   }
 }
 
-trait HailScalaModule extends SbtModule with ScalafmtModule with ScalafixModule { outer =>
+trait HailScalaModule extends ScalafmtModule with ScalafixModule { outer =>
   override def scalaVersion: T[String] = build.env.scalaVersion()
 
   override def javacOptions: T[Seq[String]] = Seq(
@@ -105,7 +105,7 @@ trait HailScalaModule extends SbtModule with ScalafmtModule with ScalafixModule
   override def bspCompileClasspath: T[Agg[UnresolvedPath]] =
     super.bspCompileClasspath() ++ resources().map(p => UnresolvedPath.ResolvedPath(p.path))
 
-  trait HailTests extends SbtTests with TestNg with ScalafmtModule with ScalafixModule {
+  trait HailTests extends ScalaTests with TestNg with ScalafmtModule with ScalafixModule {
     override def forkArgs: T[Seq[String]] = Seq("-Xss4m", "-Xmx4096M")
 
     override def ivyDeps: T[Agg[Dep]] =
@@ -123,7 +123,7 @@ trait HailScalaModule extends SbtModule with ScalafmtModule with ScalafixModule
   }
 }
 
-object `package` extends RootModule with HailScalaModule { outer =>
+object `package` extends RootModule with HailScalaModule with SbtModule { outer =>
 
   object env extends Module {
     def scalaVersion: T[String] = Task.Input {
@@ -175,6 +175,10 @@ object `package` extends RootModule with HailScalaModule { outer =>
     buildInfo(),
   )
 
+  override def generatedSources: T[Seq[PathRef]] = Task {
+    Seq(`ir-gen`.generate())
+  }
+
   override def unmanagedClasspath: T[Agg[PathRef]] =
     Agg(shadedazure.assembly())
 
@@ -246,6 +250,18 @@ object `package` extends RootModule with HailScalaModule { outer =>
     PathRef(T.dest)
   }
 
+  object `ir-gen` extends HailScalaModule {
+    def ivyDeps = Agg(
+      ivy"com.lihaoyi::mainargs:0.6.2",
+      ivy"com.lihaoyi::os-lib:0.10.7",
+    )
+
+    def generate: T[PathRef] = Task {
+      runForkedTask(finalMainClass, Task.Anon { Args("--path", T.dest) })()
+      PathRef(T.dest)
+    }
+  }
+
   object memory extends JavaModule { // with CrossValue {
     override def zincIncrementalCompilation: T[Boolean] = false
 
@@ -263,7 +279,7 @@ object `package` extends RootModule with HailScalaModule { outer =>
     }
   }
 
-  object test extends HailTests {
+  object test extends HailTests with SbtTests {
     override def resources: T[Seq[PathRef]] = outer.resources() ++ super.resources()
 
     override def assemblyRules: Seq[Rule] = outer.assemblyRules ++ Seq(
diff --git a/hail/src/main/scala/is/hail/expr/ir/IR.scala b/hail/ir-gen/resources/IR.scala.template
similarity index 100%
rename from hail/src/main/scala/is/hail/expr/ir/IR.scala
rename to hail/ir-gen/resources/IR.scala.template
diff --git a/hail/ir-gen/src/Main.scala b/hail/ir-gen/src/Main.scala
new file mode 100644
index 000000000000..8e48037149d9
--- /dev/null
+++ b/hail/ir-gen/src/Main.scala
@@ -0,0 +1,14 @@
+package ir_gen
+
+import mainargs.{main, ParserForMethods}
+//import os.pwd
+
+object Main {
+  @main
+  def main(path: String) = {
+    println(s"Writing IR source files to $path, from ${os.resource / "IR.scala.template"}")
+    println(s"Pwd: ${os.pwd}")
+  }
+
+  def main(args: Array[String]): Unit = ParserForMethods(this).runOrExit(args)
+}