Discussion thread for Mill 1.0.0-RC3

[lihaoyi]

This thread is for questions, answers, and other discussions around Mill 1.0.0-RC1/RC2

Changelog for RC1 https://github.com/com-lihaoyi/mill/blob/main/changelog.adoc#100-rc1
Changelog for RC2 https://github.com/com-lihaoyi/mill/blob/main/changelog.adoc#100-rc2
Changelog for RC3 https://github.com/com-lihaoyi/mill/blob/main/changelog.adoc#100-rc3

com.lihaoyi upgrade PRs for reference:

• Update to Mill 1.0.0 sourcecode#191
• Update to Mill 1.0.0 requests-scala#201
• Update to Mill 1.0.0 scalasql#84
• Update to Mill 1.0.0 os-lib#396
• Update to Mill 1.0.0 mainargs#195
• Update to Mill 1.0.0 upickle#670
• Update to Mill 1.0.0 scalatags#288
• Update to Mill 1.0.0 fastparse#329
• Update Mill to 1.0.0 cask#169
• Update to Mill 1.0.0 fansi#124
• Update to Mill 1.0.0 geny#99
• Update to Mill 1.0.0 PPrint#154
• Update to Mill 1.0.0 utest#378

[lihaoyi]

@lolgab @joan38 could we get releases of mill-mima and mill-scalafix for 1.0.0-RC1? That would let us roll out RC1 across the rest of the com-lihaoyi projects

[joan38]

And also com.goyeau::mill-git::0.2.7-18-d218ffa-SNAPSHOT

[lolgab]

com.github.lolgab::mill-mima_mill1.0.0-RC1:0.2.0-M1

was just published 👍

[lihaoyi]

@joan38 I'm not seeing the mill-scalafix artifacts on Maven Central https://repo1.maven.org/maven2/com/goyeau/

[joan38]

It's a snapshot right now so it's on https://oss.sonatype.org/content/repositories/snapshots

See example usage here

[lolgab]

com.github.lolgab::mill-mima::0.2.0-M3 Released for Mill 1.0.0-RC2

[rgwilton]

Where would be the best place to make recommendations about documentation related to the 1.0.0 release please?

E.g., you can select a mill version to view the documentation, but the search runs across all versions. This can be quite confusing for this changed or removed between the 0.12 and main/1.0.0 code bases.

There are sometimes other small nits or potential omissions that I spot when reading the documentation. E.g., I don't think that I can find any reference to "os.checker.withValue(os.Checker.Nop)" in the documentation, only the 1.0.0 candidate release notes.

Is flagging them here most useful, or just raising issues, or something else (and probably I don't have time to do a PR).

[lihaoyi]

@rgwilton this thread is the right place.

Where are you seeing os.checker.withValue? It is no longer in the 1.0.0 release notes. The replacement withFilesystemCheckerDisabled isn't documented either in the main docsite; that will come before 1.0,.0 final

[rgwilton]

I had seen it in a PR for perhaps 1.0.0-RC1 release notes, but hadn't seen/checked the latest versions.

[rgwilton]

A separate comment: "Target#apply() call cannot use method excludedPkgNames defined within the Task{...} block". I get this error message when I'm presumably trying to do something a bit funky, and it isn't entirely clear/obvious to me what isn't really allowed.

Hence, you may want to consider (i) highlighting what this error message means and why it may occur, and ways to mitigate it. E.g., I found some more useful info in this thread: #1478

[rgwilton]

In "Multi-File" Builds, it still contains:

Usage of sub-folder package.mill files is enabled by the magic import import $packages._

But I think that comment is now wrong/stale?

[rgwilton]

On "Writing Mill Plugins", it states:

This example demonstrates how to write and test Mill plugin, and publish it to Sonatype’s Maven Central so it can be used by other developers over the internet via [import $ivy](https://mill-build.org/mill/main-branch/extending/import-mvn-plugins.html).

Is "import $ivy" now stale?

[rgwilton]

It wasn't entirely obvious to me that the YAML syntax is only available for the root build.mill file. It looks like if it is in any package.mill files then it will be silently ignored?

[lihaoyi]

Thanks for the feedback, #5213 should add an error message in such cases so the mistake doesn't get ignored

[rgwilton]

Not sure that it is relevant to a Mill 1.0.0 release - but if in an implementation of a rule, I use the wrong name for a def, i.e., I'm trying to define/use a rule that doesn't exist, then I don't get any warning or error, it is just silently ignored because it never gets invoked. Is there anyway to mitigate this? Or is this just an inherent limitation in the approach?

[lihaoyi]

@rgwilton you can use an explicit override keyword if you want it to error if you got the name wrong. That's the default for Scala, but we made it optional because it ends up being very verbose in common usage

[rgwilton]

Thanks. I was wondering if it would be possible to automatically detect this in a less verbose way in future, e.g., I don't know if how you compile the build rules, but I was presuming that you are using macros/etc to analyse the code to construct the dependency graph. Hence would be it feasible for the mill compiler to warn if a method was defined in an Object but not referenced?

[lihaoyi]

@lolgab I'm hitting a hang in the mimaReportBinaryIssues task in com-lihaoyi/PPrint#154

The stack trace indicates it is somewhere in the mima logic

"execution-contexts-threadpool-1-thread-7" #25 daemon prio=5 os_prio=31 cpu=209.05ms elapsed=28.52s tid=0x000000016080bc00 nid=0x9003 waiting on condition  [0x0000000280e47000]
   java.lang.Thread.State: WAITING (parking)
	at jdk.internal.misc.Unsafe.park([email protected]/Native Method)
	- parking to wait for  <0x0000000601384588> (a java.util.concurrent.CountDownLatch$Sync)
	at java.util.concurrent.locks.LockSupport.park([email protected]/LockSupport.java:211)
	at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquire([email protected]/AbstractQueuedSynchronizer.java:715)
	at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireSharedInterruptibly([email protected]/AbstractQueuedSynchronizer.java:1047)
	at java.util.concurrent.CountDownLatch.await([email protected]/CountDownLatch.java:230)
	at com.typesafe.tools.mima.core.ClassInfo.superClasses$lzyINIT3(ClassInfo.scala:113)
	at com.typesafe.tools.mima.core.ClassInfo.superClasses(ClassInfo.scala:110)
	at com.typesafe.tools.mima.core.ClassInfo.thisAndSuperClasses$$anonfun$1(ClassInfo.scala:115)
	at com.typesafe.tools.mima.core.ClassInfo$$Lambda$5088/0x00000008015b1770.apply(Unknown Source)
	at scala.collection.Iterator$ConcatIteratorCell.headIterator(Iterator.scala:1213)
	at scala.collection.Iterator$ConcatIterator.advance$1(Iterator.scala:1177)
	at scala.collection.Iterator$ConcatIterator.hasNext(Iterator.scala:1188)
	at scala.collection.Iterator$$anon$10.hasNext(Iterator.scala:601)
	at scala.collection.IterableOnceOps.foreach(IterableOnce.scala:619)
	at scala.collection.IterableOnceOps.foreach$(IterableOnce.scala:617)
	at scala.collection.AbstractIterator.foreach(Iterator.scala:1306)
	at com.typesafe.tools.mima.core.TastyUnpickler$.com$typesafe$tools$mima$core$TastyUnpickler$$anon$1$$_$forEachClass$$anonfun$2(TastyUnpickler.scala:71)
	at com.typesafe.tools.mima.core.TastyUnpickler$$anon$1$$Lambda$5085/0x00000008015b0b98.applyVoid(Unknown Source)
	at scala.runtime.function.JProcedure1.apply(JProcedure1.java:15)
	at scala.runtime.function.JProcedure1.apply(JProcedure1.java:10)
	at scala.collection.immutable.List.foreach(List.scala:334)
	at com.typesafe.tools.mima.core.TastyUnpickler$$anon$1.forEachClass(TastyUnpickler.scala:72)
	at com.typesafe.tools.mima.core.TastyUnpickler$ClassTraverser.traverseClsDef(TastyUnpickler.scala:39)
	at com.typesafe.tools.mima.core.TastyUnpickler$Traverser.traverse(TastyUnpickler.scala:306)
	at com.typesafe.tools.mima.core.TastyUnpickler$Traverser.traversePkg$$anonfun$1(TastyUnpickler.scala:317)
	at com.typesafe.tools.mima.core.TastyUnpickler$Traverser$$Lambda$5067/0x00000008015ab3e8.applyVoid(Unknown Source)
	at scala.runtime.function.JProcedure1.apply(JProcedure1.java:15)
	at scala.runtime.function.JProcedure1.apply(JProcedure1.java:10)
	at scala.collection.immutable.List.foreach(List.scala:334)
	at com.typesafe.tools.mima.core.TastyUnpickler$Traverser.traversePkg(TastyUnpickler.scala:317)
	at com.typesafe.tools.mima.core.TastyUnpickler$ClassTraverser.traversePkg(TastyUnpickler.scala:32)
	at com.typesafe.tools.mima.core.TastyUnpickler$Traverser.traverse(TastyUnpickler.scala:305)
	at com.typesafe.tools.mima.core.TastyUnpickler$.copyAnnotations(TastyUnpickler.scala:74)
	at com.typesafe.tools.mima.core.TastyUnpickler$.unpickleClass(TastyUnpickler.scala:23)
	at com.typesafe.tools.mima.core.ClassfileParser.parseTasty(ClassfileParser.scala:150)
	at com.typesafe.tools.mima.core.ClassfileParser.parseClassAttributes$$anonfun$1(ClassfileParser.scala:60)
	at com.typesafe.tools.mima.core.ClassfileParser$$Lambda$5043/0x000000080159ac58.applyVoid(Unknown Source)
	at scala.runtime.function.JProcedure1.apply(JProcedure1.java:15)
	at scala.runtime.function.JProcedure1.apply(JProcedure1.java:10)
	at com.typesafe.tools.mima.core.ClassfileParser.parseAttributes$$anonfun$1(ClassfileParser.scala:80)
	at com.typesafe.tools.mima.core.ClassfileParser$$Lambda$5042/0x000000080159a868.apply$mcVI$sp(Unknown Source)
	at scala.runtime.java8.JFunction1$mcVI$sp.apply(JFunction1$mcVI$sp.scala:18)
	at scala.collection.immutable.Range.foreach(Range.scala:192)
	at com.typesafe.tools.mima.core.ClassfileParser.parseAttributes(ClassfileParser.scala:82)
	at com.typesafe.tools.mima.core.ClassfileParser.parseClassAttributes(ClassfileParser.scala:62)
	at com.typesafe.tools.mima.core.ClassfileParser.com$typesafe$tools$mima$core$ClassfileParser$$parseClass(ClassfileParser.scala:20)
	at com.typesafe.tools.mima.core.ClassfileParser$.parseInPlace(ClassfileParser.scala:171)
	at com.typesafe.tools.mima.core.ConcreteClassInfo.afterLoading(ClassInfo.scala:44)
	at com.typesafe.tools.mima.core.ClassInfo.superClass(ClassInfo.scala:73)
	at com.typesafe.tools.mima.core.ClassInfo.superClasses$lzyINIT3(ClassInfo.scala:112)
	at com.typesafe.tools.mima.core.ClassInfo.superClasses(ClassInfo.scala:110)
	at com.typesafe.tools.mima.core.ClassInfo.superClasses$lzyINIT3(ClassInfo.scala:112)
	at com.typesafe.tools.mima.core.ClassInfo.superClasses(ClassInfo.scala:110)
	at com.typesafe.tools.mima.core.ClassInfo.thisAndSuperClasses$$anonfun$1(ClassInfo.scala:115)
	at com.typesafe.tools.mima.core.ClassInfo$$Lambda$5088/0x00000008015b1770.apply(Unknown Source)
	at scala.collection.Iterator$ConcatIteratorCell.headIterator(Iterator.scala:1213)
	at scala.collection.Iterator$ConcatIterator.advance$1(Iterator.scala:1177)
	at scala.collection.Iterator$ConcatIterator.hasNext(Iterator.scala:1188)
	at scala.collection.Iterator$$anon$10.hasNext(Iterator.scala:601)
	at scala.collection.IterableOnceOps.foreach(IterableOnce.scala:619)
	at scala.collection.IterableOnceOps.foreach$(IterableOnce.scala:617)
	at scala.collection.AbstractIterator.foreach(Iterator.scala:1306)
	at com.typesafe.tools.mima.core.TastyUnpickler$.com$typesafe$tools$mima$core$TastyUnpickler$$anon$1$$_$forEachClass$$anonfun$2(TastyUnpickler.scala:71)
	at com.typesafe.tools.mima.core.TastyUnpickler$$anon$1$$Lambda$5085/0x00000008015b0b98.applyVoid(Unknown Source)
	at scala.runtime.function.JProcedure1.apply(JProcedure1.java:15)
	at scala.runtime.function.JProcedure1.apply(JProcedure1.java:10)
	at scala.collection.immutable.List.foreach(List.scala:334)
	at com.typesafe.tools.mima.core.TastyUnpickler$$anon$1.forEachClass(TastyUnpickler.scala:72)
	at com.typesafe.tools.mima.core.TastyUnpickler$ClassTraverser.traverseClsDef(TastyUnpickler.scala:39)
	at com.typesafe.tools.mima.core.TastyUnpickler$Traverser.traverse(TastyUnpickler.scala:306)
	at com.typesafe.tools.mima.core.TastyUnpickler$Traverser.traversePkg$$anonfun$1(TastyUnpickler.scala:317)
	at com.typesafe.tools.mima.core.TastyUnpickler$Traverser$$Lambda$5067/0x00000008015ab3e8.applyVoid(Unknown Source)
	at scala.runtime.function.JProcedure1.apply(JProcedure1.java:15)
	at scala.runtime.function.JProcedure1.apply(JProcedure1.java:10)
	at scala.collection.immutable.List.foreach(List.scala:334)
	at com.typesafe.tools.mima.core.TastyUnpickler$Traverser.traversePkg(TastyUnpickler.scala:317)
	at com.typesafe.tools.mima.core.TastyUnpickler$ClassTraverser.traversePkg(TastyUnpickler.scala:32)
	at com.typesafe.tools.mima.core.TastyUnpickler$Traverser.traverse(TastyUnpickler.scala:305)
	at com.typesafe.tools.mima.core.TastyUnpickler$Traverser.traversePkg$$anonfun$1(TastyUnpickler.scala:317)
	at com.typesafe.tools.mima.core.TastyUnpickler$Traverser$$Lambda$5067/0x00000008015ab3e8.applyVoid(Unknown Source)
	at scala.runtime.function.JProcedure1.apply(JProcedure1.java:15)
	at scala.runtime.function.JProcedure1.apply(JProcedure1.java:10)
	at scala.collection.immutable.List.foreach(List.scala:334)
	at com.typesafe.tools.mima.core.TastyUnpickler$Traverser.traversePkg(TastyUnpickler.scala:317)
	at com.typesafe.tools.mima.core.TastyUnpickler$ClassTraverser.traversePkg(TastyUnpickler.scala:32)
	at com.typesafe.tools.mima.core.TastyUnpickler$Traverser.traverse(TastyUnpickler.scala:305)
	at com.typesafe.tools.mima.core.TastyUnpickler$.copyAnnotations(TastyUnpickler.scala:74)
	at com.typesafe.tools.mima.core.TastyUnpickler$.unpickleClass(TastyUnpickler.scala:23)
	at com.typesafe.tools.mima.core.ClassfileParser.parseTasty(ClassfileParser.scala:150)
	at com.typesafe.tools.mima.core.ClassfileParser.parseClassAttributes$$anonfun$1(ClassfileParser.scala:60)
	at com.typesafe.tools.mima.core.ClassfileParser$$Lambda$5043/0x000000080159ac58.applyVoid(Unknown Source)
	at scala.runtime.function.JProcedure1.apply(JProcedure1.java:15)
	at scala.runtime.function.JProcedure1.apply(JProcedure1.java:10)
	at com.typesafe.tools.mima.core.ClassfileParser.parseAttributes$$anonfun$1(ClassfileParser.scala:80)
	at com.typesafe.tools.mima.core.ClassfileParser$$Lambda$5042/0x000000080159a868.apply$mcVI$sp(Unknown Source)
	at scala.runtime.java8.JFunction1$mcVI$sp.apply(JFunction1$mcVI$sp.scala:18)
	at scala.collection.immutable.Range.foreach(Range.scala:192)
	at com.typesafe.tools.mima.core.ClassfileParser.parseAttributes(ClassfileParser.scala:82)
	at com.typesafe.tools.mima.core.ClassfileParser.parseClassAttributes(ClassfileParser.scala:62)
	at com.typesafe.tools.mima.core.ClassfileParser.com$typesafe$tools$mima$core$ClassfileParser$$parseClass(ClassfileParser.scala:20)
	at com.typesafe.tools.mima.core.ClassfileParser$.parseInPlace(ClassfileParser.scala:171)
	at com.typesafe.tools.mima.core.ConcreteClassInfo.afterLoading(ClassInfo.scala:44)
	at com.typesafe.tools.mima.core.ClassInfo.flags(ClassInfo.scala:77)
	at com.typesafe.tools.mima.core.InfoLike.isPublic(InfoLike.scala:14)
	at com.typesafe.tools.mima.core.PackageInfo.isAccessible$1(PackageInfo.scala:82)
	at com.typesafe.tools.mima.core.PackageInfo.$anonfun$1(PackageInfo.scala:76)
	at com.typesafe.tools.mima.core.PackageInfo$$Lambda$5014/0x000000080158eb70.apply(Unknown Source)
	at scala.collection.Iterator$$anon$6.hasNext(Iterator.scala:479)
	at scala.collection.mutable.Growable.addAll(Growable.scala:61)
	at scala.collection.mutable.Growable.addAll$(Growable.scala:57)
	at scala.collection.immutable.SetBuilderImpl.addAll(Set.scala:405)
	at scala.collection.immutable.Set$.from(Set.scala:362)
	at scala.collection.IterableOnceOps.toSet(IterableOnce.scala:1469)
	at scala.collection.IterableOnceOps.toSet$(IterableOnce.scala:1469)
	at scala.collection.AbstractIterator.toSet(Iterator.scala:1306)
	at com.typesafe.tools.mima.core.PackageInfo.loop$1(PackageInfo.scala:76)
	at com.typesafe.tools.mima.core.PackageInfo.accessibleClasses$lzyINIT1(PackageInfo.scala:89)
	at com.typesafe.tools.mima.core.PackageInfo.accessibleClasses(PackageInfo.scala:74)
	at com.typesafe.tools.mima.lib.analyze.Analyzer$.analyze(Analyzer.scala:12)
	at com.typesafe.tools.mima.lib.MiMaLib.traversePackages(MiMaLib.scala:32)
	at com.typesafe.tools.mima.lib.MiMaLib.traversePackages$$anonfun$2(MiMaLib.scala:34)
	at com.typesafe.tools.mima.lib.MiMaLib$$Lambda$5022/0x0000000801590798.apply(Unknown Source)
	at scala.collection.immutable.List.flatMap(List.scala:294)
	at scala.collection.immutable.List.flatMap(List.scala:79)
	at com.typesafe.tools.mima.lib.MiMaLib.traversePackages(MiMaLib.scala:34)
	at com.typesafe.tools.mima.lib.MiMaLib.collectProblems(MiMaLib.scala:45)
	at com.github.lolgab.mill.mima.worker.MimaWorkerImpl.checkBC$1(MimaWorkerImpl.scala:51)
	at com.github.lolgab.mill.mima.worker.MimaWorkerImpl.$anonfun$3(MimaWorkerImpl.scala:57)
	at com.github.lolgab.mill.mima.worker.MimaWorkerImpl$$Lambda$4994/0x0000000801583000.apply(Unknown Source)
	at scala.collection.LinearSeqOps.foldLeft(LinearSeq.scala:183)
	at scala.collection.LinearSeqOps.foldLeft$(LinearSeq.scala:179)
	at scala.collection.immutable.List.foldLeft(List.scala:79)
	at com.github.lolgab.mill.mima.worker.MimaWorkerImpl.reportBinaryIssues(MimaWorkerImpl.scala:49)
	at com.github.lolgab.mill.mima.Mima.mimaReportBinaryIssues$$anonfun$1(Mima.scala:223)
	at com.github.lolgab.mill.mima.Mima$$Lambda$3402/0x0000000801366478.apply(Unknown Source)
	at mill.define.Task$Named.evaluate(Task.scala:342)
	at mill.define.Task$Named.evaluate$(Task.scala:327)
	at mill.define.Task$Command.evaluate(Task.scala:406)
	at mill.exec.GroupExecution.$anonfun$15(GroupExecution.scala:332)
	at mill.exec.GroupExecution$$Lambda$3960/0x0000000801409c80.apply(Unknown Source)
	at mill.exec.GroupExecution$.wrap$$anonfun$1$$anonfun$1$$anonfun$1$$anonfun$1(GroupExecution.scala:584)
	at mill.exec.GroupExecution$$$Lambda$3988/0x0000000801410da8.apply(Unknown Source)
	at mill.define.Evaluator$.withCurrentEvaluator$$anonfun$2$$anonfun$1(Evaluator.scala:124)
	at mill.define.Evaluator$$$Lambda$2921/0x00000008012a5b30.apply(Unknown Source)
	at scala.util.DynamicVariable.withValue(DynamicVariable.scala:59)
	at mill.define.Evaluator$.withCurrentEvaluator$$anonfun$2(Evaluator.scala:125)
	at mill.define.Evaluator$$$Lambda$2920/0x00000008012a5760.apply(Unknown Source)
	at scala.util.Using$.resource(Using.scala:296)
	at mill.define.Evaluator$.withCurrentEvaluator(Evaluator.scala:126)
	at mill.exec.GroupExecution$.wrap$$anonfun$1$$anonfun$1$$anonfun$1(GroupExecution.scala:591)
	at mill.exec.GroupExecution$$$Lambda$3977/0x000000080140e220.apply(Unknown Source)
	at mill.define.SystemStreams$.withStreams$$anonfun$1$$anonfun$1$$anonfun$1$$anonfun$1$$anonfun$1$$anonfun$1$$anonfun$1(SystemStreams.scala:85)
	at mill.define.SystemStreams$$$Lambda$3578/0x00000008013a1e40.apply(Unknown Source)
	at scala.util.DynamicVariable.withValue(DynamicVariable.scala:59)
	at mill.define.SystemStreams$.withStreams$$anonfun$1$$anonfun$1$$anonfun$1$$anonfun$1$$anonfun$1$$anonfun$1(SystemStreams.scala:86)
	at mill.define.SystemStreams$$$Lambda$3574/0x00000008013a0dc0.apply(Unknown Source)
	at scala.util.DynamicVariable.withValue(DynamicVariable.scala:59)
	at mill.define.SystemStreams$.withStreams$$anonfun$1$$anonfun$1$$anonfun$1$$anonfun$1$$anonfun$1(SystemStreams.scala:87)
	at mill.define.SystemStreams$$$Lambda$3564/0x000000080139f560.apply(Unknown Source)
	at scala.util.DynamicVariable.withValue(DynamicVariable.scala:59)
	at mill.define.SystemStreams$.withStreams$$anonfun$1$$anonfun$1$$anonfun$1$$anonfun$1(SystemStreams.scala:88)
	at mill.define.SystemStreams$$$Lambda$3555/0x000000080139dd18.apply(Unknown Source)
	at scala.util.DynamicVariable.withValue(DynamicVariable.scala:59)
	at scala.Console$.withErr(Console.scala:193)
	at mill.define.SystemStreams$.withStreams$$anonfun$1$$anonfun$1$$anonfun$1(SystemStreams.scala:89)
	at mill.define.SystemStreams$$$Lambda$3547/0x000000080139c198.apply(Unknown Source)
	at scala.util.DynamicVariable.withValue(DynamicVariable.scala:59)
	at scala.Console$.withOut(Console.scala:164)
	at mill.define.SystemStreams$.withStreams$$anonfun$1$$anonfun$1(SystemStreams.scala:90)
	at mill.define.SystemStreams$$$Lambda$3543/0x000000080139b118.apply(Unknown Source)
	at scala.util.DynamicVariable.withValue(DynamicVariable.scala:59)
	at scala.Console$.withIn(Console.scala:227)
	at mill.define.SystemStreams$.withStreams$$anonfun$1(SystemStreams.scala:91)
	at mill.define.SystemStreams$$$Lambda$3531/0x0000000801399598.apply(Unknown Source)
	at scala.util.DynamicVariable.withValue(DynamicVariable.scala:59)
	at mill.define.SystemStreams$.withStreams(SystemStreams.scala:92)
	at mill.exec.GroupExecution$.wrap$$anonfun$1$$anonfun$1(GroupExecution.scala:592)
	at mill.exec.GroupExecution$$$Lambda$3969/0x000000080140ca00.apply(Unknown Source)
	at scala.util.DynamicVariable.withValue(DynamicVariable.scala:59)
	at mill.exec.GroupExecution$.wrap$$anonfun$1(GroupExecution.scala:593)
	at mill.exec.GroupExecution$$$Lambda$3966/0x000000080140c1f0.apply(Unknown Source)
	at scala.util.DynamicVariable.withValue(DynamicVariable.scala:59)
	at mill.exec.GroupExecution$.wrap(GroupExecution.scala:594)
	at mill.exec.GroupExecution.executeGroup$$anonfun$1(GroupExecution.scala:345)
	at mill.exec.GroupExecution$$Lambda$3938/0x0000000801403140.applyVoid(Unknown Source)
	at scala.runtime.function.JProcedure1.apply(JProcedure1.java:15)
	at scala.runtime.function.JProcedure1.apply(JProcedure1.java:10)
	at scala.collection.immutable.Vector.foreach(Vector.scala:2125)
	at mill.exec.GroupExecution.executeGroup(GroupExecution.scala:283)
	at mill.exec.GroupExecution.executeGroupCached$$anonfun$1(GroupExecution.scala:193)
	at mill.exec.GroupExecution$$Lambda$3660/0x00000008013b5138.apply(Unknown Source)
	at mill.api.Logger.withPromptLine(Logger.scala:74)
	at mill.api.Logger.withPromptLine$(Logger.scala:12)
	at mill.internal.PrefixLogger.withPromptLine(PrefixLogger.scala:21)
	at mill.exec.GroupExecution.executeGroupCached(GroupExecution.scala:253)
	at mill.exec.GroupExecution.executeGroupCached$(GroupExecution.scala:21)
	at mill.exec.Execution.executeGroupCached(Execution.scala:17)
	at mill.exec.Execution.evaluateTerminals$1$$anonfun$1$$anonfun$1(Execution.scala:223)
	at mill.exec.Execution$$Lambda$3484/0x000000080138c9c8.apply(Unknown Source)
	at scala.concurrent.impl.Promise$Transformation.run(Promise.scala:467)
	at mill.exec.ExecutionContexts$.execute$$anonfun$1$$anonfun$2$$anonfun$1(ExecutionContexts.scala:65)
	at mill.exec.ExecutionContexts$.mill$exec$ExecutionContexts$ThreadPool$$_$execute$$anonfun$1$$anonfun$2$$anonfun$adapted$1(ExecutionContexts.scala:66)
	at mill.exec.ExecutionContexts$ThreadPool$$Lambda$3497/0x0000000801390580.apply(Unknown Source)
	at mill.define.SystemStreams$.withStreams$$anonfun$1$$anonfun$1$$anonfun$1$$anonfun$1$$anonfun$1$$anonfun$1$$anonfun$1(SystemStreams.scala:85)
	at mill.define.SystemStreams$$$Lambda$3578/0x00000008013a1e40.apply(Unknown Source)
	at scala.util.DynamicVariable.withValue(DynamicVariable.scala:59)
	at mill.define.SystemStreams$.withStreams$$anonfun$1$$anonfun$1$$anonfun$1$$anonfun$1$$anonfun$1$$anonfun$1(SystemStreams.scala:86)
	at mill.define.SystemStreams$$$Lambda$3574/0x00000008013a0dc0.apply(Unknown Source)
	at scala.util.DynamicVariable.withValue(DynamicVariable.scala:59)
	at mill.define.SystemStreams$.withStreams$$anonfun$1$$anonfun$1$$anonfun$1$$anonfun$1$$anonfun$1(SystemStreams.scala:87)
	at mill.define.SystemStreams$$$Lambda$3564/0x000000080139f560.apply(Unknown Source)
	at scala.util.DynamicVariable.withValue(DynamicVariable.scala:59)
	at mill.define.SystemStreams$.withStreams$$anonfun$1$$anonfun$1$$anonfun$1$$anonfun$1(SystemStreams.scala:88)
	at mill.define.SystemStreams$$$Lambda$3555/0x000000080139dd18.apply(Unknown Source)
	at scala.util.DynamicVariable.withValue(DynamicVariable.scala:59)
	at scala.Console$.withErr(Console.scala:193)
	at mill.define.SystemStreams$.withStreams$$anonfun$1$$anonfun$1$$anonfun$1(SystemStreams.scala:89)
	at mill.define.SystemStreams$$$Lambda$3547/0x000000080139c198.apply(Unknown Source)
	at scala.util.DynamicVariable.withValue(DynamicVariable.scala:59)
	at scala.Console$.withOut(Console.scala:164)
	at mill.define.SystemStreams$.withStreams$$anonfun$1$$anonfun$1(SystemStreams.scala:90)
	at mill.define.SystemStreams$$$Lambda$3543/0x000000080139b118.apply(Unknown Source)
	at scala.util.DynamicVariable.withValue(DynamicVariable.scala:59)
	at scala.Console$.withIn(Console.scala:227)
	at mill.define.SystemStreams$.withStreams$$anonfun$1(SystemStreams.scala:91)
	at mill.define.SystemStreams$$$Lambda$3531/0x0000000801399598.apply(Unknown Source)
	at scala.util.DynamicVariable.withValue(DynamicVariable.scala:59)
	at mill.define.SystemStreams$.withStreams(SystemStreams.scala:92)
	at mill.exec.ExecutionContexts$ThreadPool.execute$$anonfun$1$$anonfun$2(ExecutionContexts.scala:66)
	at mill.exec.ExecutionContexts$ThreadPool.execute$$anonfun$1$$anonfun$adapted$1(ExecutionContexts.scala:67)
	at mill.exec.ExecutionContexts$ThreadPool$$Lambda$3489/0x000000080138db20.apply(Unknown Source)
	at scala.util.DynamicVariable.withValue(DynamicVariable.scala:59)
	at mill.exec.ExecutionContexts$ThreadPool.execute$$anonfun$1(ExecutionContexts.scala:67)
	at mill.exec.ExecutionContexts$ThreadPool$$Lambda$3485/0x000000080138d000.apply$mcV$sp(Unknown Source)
	at mill.exec.ExecutionContexts$ThreadPool$PriorityRunnable.run(ExecutionContexts.scala:86)
	at java.util.concurrent.ThreadPoolExecutor.runWorker([email protected]/ThreadPoolExecutor.java:1136)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run([email protected]/ThreadPoolExecutor.java:635)
	at java.lang.Thread.run([email protected]/Thread.java:833)

This can be reproduced by ./mill -i 'pprint.jvm[3.3.5].mimaReportBinaryIssues'. Do you have any idea what may be causing this?

[lolgab]

It seems there is a bug with the Scala 3 version of mima. Using the 2.13 version of mima-core fixes the problem: lolgab/mill-mima#191
Going to release 0.2.0-M2 ASAP.

[lolgab]

Opened an issue in MiMa here: lightbend-labs/mima#867

[lolgab]

0.2.0-M2 is on Maven Central.

[lolgab]

Updated in utest: com-lihaoyi/utest@87463b7
Let's see if it works.

[lihaoyi]

Thanks! Looks like the Mill upgrades are green now

[Quafadas]

I'm exploring RC-1 (on windows), and have some observations;

• On first upgrade, mill simply hung. It was necessary to delete the out folder, after which it burst into life. I couldn't see this recommendation in the release notes but it might be a helpful addition to save a headscratch.
• Milll detected (by default) a terribly old JVM version which was causing weirdness and I had to dig into the mill config files to figure it out. It's certainly possible, that this behavior is in fact the same as previously - and that new mill's transparency is simply offering a better path to detection. It could be that explicitly specifying the JVM version in frontmatter is a good recommendation, and maybe should be common in the examples
• Forcing mill to use jvm 24 yielded the following;

WARNING: A restricted method in java.lang.System has been called
WARNING: java.lang.System::load has been called by coursier.jniutils.LoadWindowsLibrary in an unnamed module (file:/C:/Users/partens/AppData/Local/Coursier/cache/v1/https/packages.corp.com/artifactory/maven/io/get-coursier/jniutils/windows-jni-utils/0.3.3/windows-jni-utils-0.3.3.jar)
WARNING: Use --enable-native-access=ALL-UNNAMED
 to avoid a warning for callers in this module
WARNING: Restricted methods will be blocked in a future release unless native access is enabled

Perhaps this comes from scala itself?

• Getting some funny characters emitted in error messages, which are prefixed with some funky characters
  [error] Γöé
• Errors in the frontmatter, currently come with rather cryptic error messages;

//| repositories: https://packages.corp.com/artifactory/maven

will get you this;

PS C:\temp\millSite> mill resolve _
[47/66] ============================== resolve _ ==============================
An unexpected error occurred upickle.core.Abort: expected sequence got string
upickle.core.SimpleVisitor.visitString(SimpleVisitor.scala:14)

What you need, is this;

//| repositories: [https://packages.corp.com/artifactory/maven]

But if you aren't making small incremental changes, tracking that back is not entirely obvious.

I'm now at the stage of wading through build errors (which is good) but wanted to post these things here before I forget them, I don't think any are "dealbreaking" .

[lefou]

If this is a CoursierModule, you should be able to use:

def linkerLibs = Task {
  defaultResolver().classpath(linkerDependency())
}

[Quafadas]

I think I'm down to two things that I can't find in the release notes;

Is T.persistent still a thing?

def mdoc: Task[PathRef] = Task(persistent = true){

Can I still get a zincWorker()?
It's right therre in the release notes; jvmWorker()

[Quafadas]

@lefou - thanks - cross posted...

[Quafadas]

Plugin now compiles, the release notes are really good. It's quite a bit to absorb is all.

[Quafadas]

Struggling with integration testing a plugin on windows, can't get past this and not quite sure where the error is.

Exception in thread "subprocess-shutdown-hook-monitor" java.io.IOException: Cannot run program "C:\temp\millSite\out\plugin\test\millExecutable\assembly.dest\out.jar" (in directory "C:\temp\millSite\out\plugin\test\testForked.dest\sandbox\run-1"): CreateProcess error=193, %1 is not a valid Win32 application

Will try on mac later

[Quafadas]

I have this unit test for a plugin, which worked in mill 0.12 series.

object SimpleTest extends TestSuite:

  def tests: Tests = Tests {
    test("simple") {

      object wrapper extends TestRootModule:
        object foo extends SimpleModule:
          override def scalaVersion = "3.3.4"
        end foo

        object simples extends ScalaModule with SiteModule:
          override def scalaVersion = "3.3.4"
          override def moduleDeps = Seq(foo)
        end simples
      end wrapper
      val resourceFolder = os.Path(sys.env("MILL_TEST_RESOURCE_DIR"))    
      UnitTester(wrapper, resourceFolder / "01-simple").scoped { eval =>
///...etc
}}

In the mill 1.0.0 series, it appears to fail at compile time.

While expanding a macro, a reference to object **foo** was used outside the scope where it was defined
While expanding a macro, a reference to object **simples** was used outside the scope where it was defined

Is this. known / intentional? Or have I messed up? I can't see where...

[lihaoyi]

Did you try adding a def millDiscover = mill.define.Discover[this.type] definition to make the compiler error go away?

[Quafadas]

I did, although this appeared to lead down a different rabbit hole. A naive attempt yields this;

Target definitions must have 0 parameter lists

Which I interpreted to mean that there might have been something wrong with the build definition, so I tried to remove out anything related to my own build definition, i.e. down to this;

object SimpleTest extends TestSuite {

  object wrapper extends TestRootModule {

    def millDiscover = mill.define.Discover[this.type]

    object foo extends ScalaModule {
      override def scalaVersion = "3.3.4"
    }
  }

  def tests: Tests = Tests {
    test("simple") {

Which yielded another comple error, and at which point, I stopped uncertain with that direction of travel.

But, knowing that should work, is enough to work around the follow up compile error for a vanilla build model;

No mainargs.TokensReader[mill.define.Task[mill.Args]] found for parameter args of method run in mill.scalalib.RunModule

By copy-pasting these lines from the sources mill generates from a successfully processed build.mill.

import _root_.mill.util.TokenReaders.given
import _root_.mill.define.JsonFormatters.given

And from there I could prove I've done something wrong in defining the actual plugin too, so I'm currently trying to figure out what the offending target is, but I think that hint was enough, thankyou.

[Quafadas]

Eventually tracked back to a rogue pair of brackets.

def linkerLibs() = Task { gets the error message.

def linkerLibs = Task { is fine.

[lihaoyi]

@Quafadas sounds like the error message for parentheses could be improved. Can you open an issue so we don't forget?

[Quafadas]

DOne - #5284 - thanks again for the hints

[lihaoyi]

1.0.0-RC2 is out https://github.com/com-lihaoyi/mill/blob/main/changelog.adoc#100-rc2

[lolgab]

mill-mima update: lolgab/mill-mima#194

[rgwilton]

When I use --watch, it works as expected for a while, and then after a few minutes (probably less than 10 minutes), mill seems to silently exit back to the shell with no errors. This is on rc2 on Mac OS X. Note: I didn't test on on rc1, so no idea if this is a change since the first release candidate.

This is for a scala server + scalajs project:
./mill --watch server.runBackground

[lihaoyi]

@rgwilton thanks for the report, you should be hitting #5225. For now you can work around it by --notify-watch false from the ckmmand line or .mill-opts file

[lihaoyi]

I'm trying to rebootstrap Mill in preparation for releasing 1.0.0 but hit this issue #5398 that is likely a blocker for the release

[lefou]

I think we need to review all open scheduled issues for the current milestone.

https://github.com/com-lihaoyi/mill/issues?q=is%3Aopen%20milestone%3A%221.0.0-RC3%22

EDIT: E.g. #5302 is a real blocker. We should make sure, the setup works, e.g. by applying it to detect (warn-level) changes between RC2 and RC3.

And given the many changes since RC2, we might just cut a RC3 and wait one or two days for feedback before cutting the final 1.0.0.

[lihaoyi]

Sure cutting an RC3 sounds reasonable. Will do so after the rebootstrapping issue is resolved

[lihaoyi]

The open issue list looks pretty good. #5302 we can do post-release (since that will need mill-mima published), #4716 I've taken a few passes but you can take a pass as well. #4338 #3570 #3567 I think we don't need to solve right now, so even though they are nice to have I don't think they need to hold up the release

[lihaoyi]

Seems the next steps for 1.0.0 are:

1. Fix Performance regression in coursier code paths on Windows #5398
2. Publish 1.0.0-RC3
3. Re-publish mill-mima and mill-scalafix for 1.0.0-RC3
4. Manually test mill-mima to make sure it catches bincompat breakages Reenable binary compatibility checks #5302
5. Roll out 1.0.0-RC3 across the com-lihaoyi projects
6. Publish 1.0.0-final
7. Re-publish mill-mima and mill-scalafix for 1.0.0
8. Roll out 1.0.0 across the com-lihaoyi projects
9. Announce 1.0.0 for use

[lihaoyi]

1.0.0-RC3 is out. @joan38 @lolgab could we get releases of mill-scalafix and mill-mima for 1.0.0-RC3?

[lolgab]

mill-mima 0.2.0-M4 is on its way to Maven Central.

[lihaoyi]

@lolgab looks like there was some failure publishing https://github.com/lolgab/mill-mima/actions/runs/16023323319/job/45205304488

[lihaoyi]

Did you migrate to sonatype central for publishing? sonatype central has a different token from the old OSSRH, so if you migrated you would need to change the token in your github action secrets

[lolgab]

I published the other releases successfully with Sonatype Central. Thank you.
Some days ago I did reset the credentials and forgot to update them in mill-mima actions secrets.

[lihaoyi]

Thanks, I got it!

[lihaoyi]

Aiming to publish Mill 1.0.0 final on 10 July 2025, so please try out 1.0.0-RC3 if you have a chance!

[lihaoyi]

1.0.0 is out, @lolgab @joan38 could we get mill-mima and mill-scalafix published for 1.0.0? Thanks!

[joan38]

Doing it today