Upgrade to Scala 3.7.0-RC1

build.mill

@@ -4,7 +4,7 @@ import com.github.lolgab.mill.mima.Mima
 import coursier.maven.MavenRepository
 import de.tobiasroeser.mill.vcs.version.VcsVersion
 import com.goyeau.mill.scalafix.ScalafixModule
-import mill._
+import mill.{idea => _, _}
 import mill.define.NamedTask
 import mill.main.Tasks
 import mill.scalalib._
@@ -51,7 +51,7 @@ object Deps {
   // The Scala version to use
   // When updating, run "Publish Bridges" Github Actions for the new version
   // and then add to it `bridgeScalaVersions`
-  val scalaVersion = "3.6.2"
+  val scalaVersion = "3.7.0-RC1"
   val scala2Version = "2.13.15"
   // The Scala 2.12.x version to use for some workers
   val workerScalaVersion212 = "2.12.20"
@@ -162,7 +162,7 @@ object Deps {
   val osLib = ivy"com.lihaoyi::os-lib:0.11.5-M2"
   val pprint = ivy"com.lihaoyi::pprint:0.9.0"
   val mainargs = ivy"com.lihaoyi::mainargs:0.7.6"
-  val millModuledefsVersion = "0.11.3-M5"
+  val millModuledefsVersion = "0.11.3-M7"
   val millModuledefsString = s"com.lihaoyi::mill-moduledefs:${millModuledefsVersion}"
   val millModuledefs = ivy"${millModuledefsString}"
   val millModuledefsPlugin =
@@ -489,17 +489,18 @@ trait MillScalaModule extends ScalaModule with MillJavaModule with ScalafixModul
   def scalacOptions =
     super.scalacOptions() ++ Seq(
       "-deprecation",
-      "-feature"
+      "-feature",
     ) ++ (
       if (ZincWorkerUtil.isScala3(scalaVersion())) Seq(
+        "-experimental",
         // "-Werror",
-        "-Wunused:all",
+//        "-Wunused:all",
         // "-Xfatal-warnings",
-        "-Wconf:msg=An existential type that came from a Scala-2 classfile:silent",
-        "-Wconf:msg=import scala.language.implicitConversions:silent",
-        "-Wconf:msg=IterableOnceExtensionMethods:silent",
-        "-Wconf:msg=is deprecated:silent",
-        "-Wconf:msg=cannot be checked at runtime:silent"
+//        "-Wconf:msg=An existential type that came from a Scala-2 classfile:silent",
+//        "-Wconf:msg=import scala.language.implicitConversions:silent",
+//        "-Wconf:msg=IterableOnceExtensionMethods:silent",
+//        "-Wconf:msg=is deprecated:silent",
+//        "-Wconf:msg=cannot be checked at runtime:silent"
         // "-Wconf:msg=unused:silent"
         // "-no-indent",
         // "-Wvalue-discard",

ci/mill-bootstrap.patch

@@ -37,7 +37,7 @@ index 92bfb2c2f8f..9854c30dac1 100644
 -import com.goyeau.mill.scalafix.ScalafixModule
 +//import de.tobiasroeser.mill.vcs.version.VcsVersion
 +//import com.goyeau.mill.scalafix.ScalafixModule
- import mill._
+ import mill.{idea => _, _}
  import mill.define.NamedTask
  import mill.main.Tasks
  import mill.scalalib._

core/api/src/mill/api/ExecResult.scala

@@ -123,18 +123,4 @@ object ExecResult {
     }
   }
 
-  def catchWrapException[T](t: => T): Result[T] = {
-    try mill.api.Result.Success(t)
-    catch {
-      case e: InvocationTargetException =>
-        mill.api.Result.Failure(makeResultException(e.getCause, new java.lang.Exception()).left.get)
-      case e: Exception =>
-        mill.api.Result.Failure(makeResultException(e, new java.lang.Exception()).left.get)
-    }
-  }
-
-  def makeResultException(e: Throwable, base: java.lang.Exception): Left[String, Nothing] = {
-    val outerStack = new mill.api.ExecResult.OuterStack(base.getStackTrace)
-    Left(mill.api.ExecResult.Exception(e, outerStack).toString)
-  }
 }

core/api/src/mill/api/MillException.scala

@@ -1,14 +1,43 @@
 package mill.api
 
+
+import java.lang.reflect.InvocationTargetException
+
 /**
  * This exception is specifically handled in [[mill.runner.MillMain]] and [[mill.runner.MillServerMain]]. You can use it, if you need to exit Mill with a nice error message.
+ *
  * @param msg The error message, to be displayed to the user.
  */
 class MillException(msg: String) extends Exception(msg)
 
+object MillException {
+
+  def catchWrapException[T](t: => T): Result[T] = {
+    try mill.api.Result.Success(t)
+    catch { case e =>
+        mill.api.Result.Failure(
+          makeResultException(e, new java.lang.Exception()).toString
+        )
+    }
+  }
+
+  def unwrapException(t: Throwable) = t match {
+    case e: ExceptionInInitializerError if e.getCause != null => e.getCause
+    case e: InvocationTargetException if e.getCause != null => e.getCause
+    case e: NoClassDefFoundError if e.getCause != null => e.getCause
+    case e => e
+  }
+
+  def makeResultException(e: Throwable, base: java.lang.Exception): mill.api.ExecResult.Exception = {
+    val outerStack = new mill.api.ExecResult.OuterStack(base.getStackTrace)
+    mill.api.ExecResult.Exception(unwrapException(e), outerStack)
+  }
+}
+
+
 class BuildScriptException(msg: String, script: Option[String])
-    extends MillException(
-      script.map(_ + ": ").getOrElse("") + "Build script contains errors:\n" + msg
-    ) {
+  extends MillException(
+    script.map(_ + ": ").getOrElse("") + "Build script contains errors:\n" + msg
+  ) {
   def this(msg: String) = this(msg, None)
 }

core/constants/src/mill/constants/CodeGenConstants.java

@@ -9,7 +9,7 @@ public class CodeGenConstants {
    * we import to work around the need for the `.package` suffix, so
    * we add an `_` and call it `build_`
    */
-  public static final String globalPackagePrefix = "build_";
+  public static final String globalPackagePrefix = "build";
 
   /**
    * What the wrapper objects are called. Not `package` because we don't

core/define/src/mill/define/BaseModule.scala

@@ -25,7 +25,7 @@ abstract class BaseModule(
 
   // `Discover` needs to be defined by every concrete `BaseModule` object, to gather
   // compile-time metadata about the tasks and commands at for use at runtime
-  protected def millDiscover: Discover
+  protected[mill] def millDiscover: Discover
 
   // We need to propagate the `Discover` object implicitly throughout the module tree
   // so it can be used for override detection

core/define/src/mill/define/Discover.scala

@@ -15,15 +15,20 @@ import scala.collection.mutable
  * can then be used later to look up the `MainData` for any module.
  */
 class Discover(val classInfo: Map[Class[?], Discover.ClassInfo]) {
-  def resolveEntrypoint(cls: Class[?], name: String) = {
-    val res = for {
-      (cls2, node) <- classInfo
+  def resolveClassInfo(cls: Class[?]) = {
+    for {
+      (cls2, node) <- classInfo.iterator
       if cls2.isAssignableFrom(cls)
+    } yield (cls2, node)
+  }
+  def resolveEntrypoint(cls: Class[?], name: String) = {
+    val res = for{
+      (cls2, node) <- resolveClassInfo(cls)
       ep <- node.entryPoints
       if ep.mainName.getOrElse(ep.defaultName) == name
     } yield ep
 
-    res.headOption
+    res.nextOption
   }
 }
 

core/define/src/mill/define/internal/Reflect.scala

@@ -44,7 +44,7 @@ private[mill] object Reflect {
     val arr: Array[java.lang.reflect.Method] = getMethods(outer)
       .collect {
         case (m, n)
-            if filter(n) &&
+            if filter(n.stripSuffix("_alias")) &&
               (!noParams || m.getParameterCount == 0) &&
               inner.isAssignableFrom(m.getReturnType) =>
           m
@@ -94,7 +94,7 @@ private[mill] object Reflect {
       noParams = true,
       getMethods
     )
-      .map(m => (m.getName, m))
+      .map(m => (m.getName.stripSuffix("_alias"), m))
 
     val companionClassOpt = outerCls.getName match {
       case s"$prefix$$" =>
@@ -107,18 +107,25 @@ private[mill] object Reflect {
       .filter(implicitly[ClassTag[T]].runtimeClass.isAssignableFrom(_))
       .flatMap { c =>
         c.getName.stripPrefix(outerCls.getName) match {
-          case s"$name$$" if filter(scala.reflect.NameTransformer.decode(name)) =>
+          case s"$name$$" if filter(scala.reflect.NameTransformer.decode(name).stripSuffix("_alias")) =>
             c.getFields.find(f => f.getName == "MODULE$").map(name -> _)
           case _ => None
         }
 
       }
       .distinct
 
+    val third = outerCls.getFields
+      .filter(f => implicitly[ClassTag[T]].runtimeClass.isAssignableFrom(f.getType) && f.getName != "MODULE$")
+      .map(f => scala.reflect.NameTransformer.decode(f.getName) -> f.getType.getField("MODULE$"))
+      .filter(t => filter(t._1))
+
     // Sometimes `getClasses` returns stuff in odd orders, make sure to sort for determinism
     second.sortInPlaceBy(_._1)
 
-    first ++ second
+    val res: Array[(String, java.lang.reflect.Member)] = (first ++ second ++ third)
+
+    res.distinctBy(_._1)
   }
 
   def reflectNestedObjects02[T: ClassTag](

core/define/test/src/mill/define/MacroErrorTests.scala

@@ -10,13 +10,13 @@ object MacroErrorTests extends TestSuite {
       val expectedMsg =
         "Task{} members must be defs defined in a Module class/trait/object body"
 
-      val err = compileError("object Foo extends TestBaseModule{ val x = Task {1} }")
+      val err: utest.CompileError = compileError("object Foo extends TestBaseModule{ val x = Task {1} }")
       assert(err.msg == expectedMsg)
     }
 
     test("badParameterSets") {
       test("command") {
-        val e = compileError("""
+        val e: utest.CompileError = compileError("""
           object foo extends TestBaseModule{
             def w = Task.Command{1}
             lazy val millDiscover = Discover[this.type]
@@ -30,7 +30,7 @@ object MacroErrorTests extends TestSuite {
       }
 
       test("target") {
-        val e = compileError("""
+        val e: utest.CompileError = compileError("""
           object foo extends TestBaseModule{
             def x() = Task {1}
             lazy val millDiscover = Discover[this.type]
@@ -43,7 +43,7 @@ object MacroErrorTests extends TestSuite {
         )
       }
       test("input") {
-        val e = compileError("""
+        val e: utest.CompileError = compileError("""
           object foo extends TestBaseModule{
             def y() = Task.Input{1}
             lazy val millDiscover = Discover[this.type]
@@ -56,7 +56,7 @@ object MacroErrorTests extends TestSuite {
         )
       }
       test("sources") {
-        val e = compileError("""
+        val e: utest.CompileError = compileError("""
           object foo extends TestBaseModule{
             def z() = Task.Sources{os.pwd}
             lazy val millDiscover = Discover[this.type]
@@ -69,7 +69,7 @@ object MacroErrorTests extends TestSuite {
         )
       }
       test("persistent") {
-        val e = compileError("""
+        val e: utest.CompileError = compileError("""
           object foo extends TestBaseModule{
             def a() = Task(persistent = true){1}
             lazy val millDiscover = Discover[this.type]
@@ -101,14 +101,14 @@ object MacroErrorTests extends TestSuite {
         }
       }
       test("neg1") {
-        val e = compileError("""def a = Task { 1 }""")
+        val e: utest.CompileError = compileError("""def a = Task { 1 }""")
         assert(e.msg.contains(
           "Task{} members must be defs defined in a Module class/trait/object body"
         ))
       }
 
       test("neg2") {
-        val e = compileError("object foo extends TestBaseModule{ val a = Task { 1 } }")
+        val e: utest.CompileError = compileError("object foo extends TestBaseModule{ val a = Task { 1 } }")
         assert(e.msg.contains(
           "Task{} members must be defs defined in a Module class/trait/object body"
         ))
@@ -117,7 +117,7 @@ object MacroErrorTests extends TestSuite {
 
         val expectedMsg =
           "Target#apply() call cannot use `val n` defined within the Task{...} block"
-        val err = compileError("""
+        val err: utest.CompileError = compileError("""
           object foo extends TestBaseModule{
             def a = Task { 1 }
             val arr = Array(a)
@@ -136,7 +136,7 @@ object MacroErrorTests extends TestSuite {
 
         val expectedMsg =
           "Target#apply() call cannot use `val x` defined within the Task{...} block"
-        val err = compileError("""
+        val err: utest.CompileError = compileError("""
           object foo extends TestBaseModule{
             def a = Task { 1 }
             val arr = Array(a)
@@ -166,7 +166,7 @@ object MacroErrorTests extends TestSuite {
     }
 
     test("badCrossKeys") {
-      val error = utest.compileError(
+      val error: utest.CompileError = utest.compileError(
         """
         object foo extends TestBaseModule{
           object cross extends Cross[MyCrossModule](Seq(1, 2, 3))
@@ -181,7 +181,7 @@ object MacroErrorTests extends TestSuite {
     }
 
     test("badCrossKeys2") {
-      val error = utest.compileError(
+      val error: utest.CompileError = utest.compileError(
         """
         object foo extends TestBaseModule{
           object cross extends Cross[MyCrossModule](Seq((1, 2), (2, 2), (3, 3)))
@@ -202,7 +202,7 @@ object MacroErrorTests extends TestSuite {
     }
 
     test("invalidCrossType") {
-      val error = utest.compileError(
+      val error: utest.CompileError = utest.compileError(
         """
         object foo extends TestBaseModule{
           object cross extends Cross[MyCrossModule](null.asInstanceOf[sun.misc.Unsafe])

core/exec/src/mill/exec/Execution.scala

@@ -221,7 +221,8 @@ private[mill] case class Execution(
               }
             } catch {
               case e: Throwable if !scala.util.control.NonFatal(e) =>
-                throw new Exception(e)
+                if (e.getCause != null) throw e.getCause
+                else throw new Exception(e)
             }
           }
         }

core/resolve/src/mill/resolve/Resolve.scala

@@ -13,7 +13,8 @@ import mill.define.{
   SelectMode
 }
 import mill.api.Result
-import mill.resolve.ResolveCore.{Resolved, makeResultException}
+import mill.resolve.ResolveCore.Resolved
+import mill.api.MillException.{catchWrapException, makeResultException}
 
 private[mill] object Resolve {
   object Segments extends Resolve[Segments] {
@@ -58,9 +59,11 @@ private[mill] object Resolve {
 
       val taskList: Seq[Result[Option[NamedTask[?]]]] = resolved.map {
         case r: Resolved.NamedTask =>
-          val instantiated = ResolveCore
-            .instantiateModule(rootModule, r.segments.init, cache)
-            .flatMap(instantiateNamedTask(r, _, cache))
+          val instantiated = catchWrapException {
+            ResolveCore
+              .instantiateModule(rootModule, r.segments.init, cache)
+              .flatMap(instantiateNamedTask(r, _, cache))
+          }.flatMap(identity)
           instantiated.map(Some(_))
 
         case r: Resolved.Command =>
@@ -136,7 +139,7 @@ private[mill] object Resolve {
       )
       .head
 
-    ResolveCore.catchWrapException(
+    catchWrapException(
       definition.invoke(p).asInstanceOf[NamedTask[?]]
     )
   }
@@ -149,7 +152,7 @@ private[mill] object Resolve {
       nullCommandDefaults: Boolean,
       allowPositionalCommandArgs: Boolean
   ) = {
-    ResolveCore.catchWrapException {
+    catchWrapException {
       val invoked = invokeCommand0(
         p,
         r.segments.last.value,
@@ -208,7 +211,7 @@ private[mill] object Resolve {
     } match {
       case mainargs.Result.Success(v: Command[_]) => Result.Success(v)
       case mainargs.Result.Failure.Exception(e) =>
-        Result.Failure(makeResultException(e, new Exception()).left.get)
+        Result.Failure(makeResultException(e, new Exception()).toString)
       case f: mainargs.Result.Failure =>
         Result.Failure(
           mainargs.Renderer.renderResult(