Revert zinc to 1.9.6 to fix incremental compilation in the build

build.mill

@@ -55,12 +55,12 @@ 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 = "2.13.14"
-  val scala2Version = "2.13.14"
+  val scalaVersion = "2.13.13"
+  val scala2Version = "2.13.13"
   // The Scala 2.12.x version to use for some workers
   val workerScalaVersion212 = "2.12.19"
 
-  val testScala213Version = "2.13.14"
+  val testScala213Version = "2.13.13"
   // Scala Native 4.2 will not get releases for new Scala version
   val testScala213VersionForScalaNative42 = "2.13.8"
   val testScala212Version = "2.12.6"
@@ -179,7 +179,7 @@ object Deps {
   val sourcecode = ivy"com.lihaoyi::sourcecode:0.3.1"
   val upickle = ivy"com.lihaoyi::upickle:3.3.1"
   val windowsAnsi = ivy"io.github.alexarchambault.windows-ansi:windows-ansi:0.0.5"
-  val zinc = ivy"org.scala-sbt::zinc:1.10.2"
+  val zinc = ivy"org.scala-sbt::zinc:1.9.6"
   // keep in sync with doc/antora/antory.yml
   val bsp4j = ivy"ch.epfl.scala:bsp4j:2.2.0-M2"
   val fansi = ivy"com.lihaoyi::fansi:0.5.0"
@@ -416,7 +416,7 @@ trait MillScalaModule extends ScalaModule with MillJavaModule with ScalafixModul
       "-feature",
       "-Xlint:unused",
       "-Xlint:adapted-args",
-      "-Xsource:3",
+//      "-Xsource:3",
       "-Wconf:msg=inferred type changes:silent",
       "-Wconf:msg=case companions no longer extend FunctionN:silent",
       "-Wconf:msg=access modifiers for:silent",

ci/test-mill-bootstrap.sh

@@ -18,6 +18,8 @@ git stash pop "$(git stash list | grep "preserve mill-release" | head -n1 | sed
 # Prepare local build
 ci/prepare-mill-bootstrap.sh
 
+rm -rf out
+
 # Run tests
 target/mill-release -i "__.compile"
 target/mill-release -i "example.scalalib.basic[1-simple].server.test"

example/scalalib/basic/1-simple/build.mill

@@ -3,7 +3,7 @@ package build
 import mill._, scalalib._
 
 object `package` extends RootModule with ScalaModule {
-  def scalaVersion = "2.13.11"
+  def scalaVersion = "2.13.15"
   def ivyDeps = Agg(
     ivy"com.lihaoyi::scalatags:0.12.0",
     ivy"com.lihaoyi::mainargs:0.6.2"

integration/invalidation/codesig-subfolder/src/CodeSigSubfolderTests.scala

@@ -46,19 +46,15 @@ object CodeSigSubfolderTests extends UtestIntegrationTestSuite {
       // Changing stuff in subfolder/package.mill does not invalidate unrelated tasks in build.mill
       val cached3 = eval("foo")
       assert(cached3.out == "")
-      // This should only compile 1 source but it seems there's an upstream bug in Zinc
-      // https://github.com/sbt/zinc/issues/1461
-      assert(cached3.err.contains("compiling 2 Scala sources"))
+      assert(cached3.err.contains("compiling 1 Scala source"))
 
       modifyFile(
         workspacePath / "subfolder/package.mill",
         _.replace("running helperFoo", "running helperFoo2")
       )
       val mangledHelperFoo = eval("foo")
       assert(mangledHelperFoo.out.linesIterator.toSeq == Seq("running foo2", "running helperFoo2"))
-      // This should only compile 1 source but it seems there's an upstream bug in Zinc
-      // https://github.com/sbt/zinc/issues/1461
-      assert(mangledHelperFoo.err.contains("compiling 2 Scala sources"))
+      assert(mangledHelperFoo.err.contains("compiling 1 Scala source"))
 
       // Make sure changing `val`s, which only affects the Module constructor and
       // not the Task method itself, causes invalidation
@@ -68,9 +64,8 @@ object CodeSigSubfolderTests extends UtestIntegrationTestSuite {
       )
       val mangledValFoo = eval("foo")
       assert(mangledValFoo.out.linesIterator.toSeq == Seq("running foo2", "running helperFoo2"))
-      // This should only compile 1 source but it seems there's an upstream bug in Zinc
-      // https://github.com/sbt/zinc/issues/1461
-      assert(mangledValFoo.err.contains("compiling 2 Scala sources"))
+
+      assert(mangledValFoo.err.contains("compiling 1 Scala source"))
 
       // Even modifying `val`s that do not affect the task invalidates it, because
       // we only know that the constructor changed and don't do enough analysis to
@@ -85,9 +80,7 @@ object CodeSigSubfolderTests extends UtestIntegrationTestSuite {
         "running helperFoo2"
       ))
 
-      // This should only compile 1 source but it seems there's an upstream bug in Zinc
-      // https://github.com/sbt/zinc/issues/1461
-      assert(mangledValFooUsedInBar.err.contains("compiling 2 Scala sources"))
+      assert(mangledValFooUsedInBar.err.contains("compiling 1 Scala source"))
 
       val cached4 = eval("foo")
       assert(cached4.out == "")

integration/invalidation/zinc-build-compilation/resources/build.mill

@@ -5,4 +5,4 @@ import mill._
 
 def foo = { println("running foo"); build_.subfolder.package_.helperFoo }
 
-def dummy = Task{ 1 }
+def dummy = Task{ 1 }

integration/invalidation/zinc-build-compilation/src/ZincBuildCompilationTests.scala

@@ -31,10 +31,8 @@ object ZincBuildCompilationTests extends UtestIntegrationTestSuite {
         _.replace("running helperFoo", "running helperFoo2")
       )
       val mangledHelperFoo = eval(("dummy"))
-      // This should only compile 1 source but it seems there's an upstream bug in Zinc
-      // https://github.com/sbt/zinc/issues/1461
-      assert(mangledHelperFoo.err.contains("compiling 2 Scala source"))
 
+      assert(mangledHelperFoo.err.contains("compiling 1 Scala source"))
     }
   }
 }

runner/src/mill/runner/MillBuildBootstrap.scala

@@ -2,7 +2,7 @@ package mill.runner
 
 import mill.util.{ColorLogger, PrefixLogger, Watchable}
 import mill.main.{BuildInfo, RootModule, RunScript}
-import mill.main.client.CodeGenConstants.*
+import mill.main.client.CodeGenConstants._
 import mill.api.{PathRef, SystemStreams, Val, internal}
 import mill.eval.Evaluator
 import mill.resolve.SelectMode

scalalib/worker/src/mill/scalalib/worker/ZincWorkerImpl.scala

@@ -13,6 +13,7 @@ import mill.scalalib.api.{CompilationResult, Versions, ZincWorkerApi, ZincWorker
 import sbt.internal.inc.{
   Analysis,
   CompileFailed,
+  FileAnalysisStore,
   FreshCompilerCache,
   ManagedLoggedReporter,
   MappedFileConverter,
@@ -22,13 +23,10 @@ import sbt.internal.inc.{
   javac
 }
 import sbt.internal.inc.classpath.ClasspathUtil
-import sbt.internal.inc.consistent.ConsistentFileAnalysisStore
 import sbt.internal.util.{ConsoleAppender, ConsoleOut}
 import sbt.mill.SbtLoggerUtils
-import xsbti.compile.analysis.ReadWriteMappers
 import xsbti.compile.{
   AnalysisContents,
-  AnalysisStore,
   AuxiliaryClassFileExtension,
   ClasspathOptions,
   CompileAnalysis,
@@ -333,7 +331,7 @@ class ZincWorkerImpl(
   def discoverMainClasses(compilationResult: CompilationResult): Seq[String] = {
     def toScala[A](o: Optional[A]): Option[A] = if (o.isPresent) Some(o.get) else None
 
-    toScala(fileAnalysisStore(compilationResult.analysisFile).get())
+    toScala(FileAnalysisStore.binary(compilationResult.analysisFile.toIO).get())
       .map(_.getAnalysis)
       .flatMap {
         case analysis: Analysis =>
@@ -474,14 +472,6 @@ class ZincWorkerImpl(
     }(f)
   }
 
-  private def fileAnalysisStore(path: os.Path): AnalysisStore =
-    ConsistentFileAnalysisStore.binary(
-      file = path.toIO,
-      mappers = ReadWriteMappers.getEmptyMappers(),
-      // No need to utilize more that 8 cores to serialize a small file
-      parallelism = math.min(Runtime.getRuntime.availableProcessors(), 8)
-    )
-
   private def compileInternal(
       upstreamCompileOutput: Seq[CompilationResult],
       sources: Agg[os.Path],
@@ -493,7 +483,7 @@ class ZincWorkerImpl(
       reportCachedProblems: Boolean,
       incrementalCompilation: Boolean,
       auxiliaryClassFileExtensions: Seq[String],
-      zincCache: os.SubPath = os.sub / "zinc"
+      zincFile: os.SubPath = os.sub / "zinc"
   )(implicit ctx: ZincWorkerApi.Ctx): Result[CompilationResult] = {
     os.makeDir.all(ctx.dest)
 
@@ -559,14 +549,14 @@ class ZincWorkerImpl(
         case _ => None
       }
       analysisFile match {
-        case Some(zincPath) => fileAnalysisStore(zincPath).get().map(_.getAnalysis)
+        case Some(zincPath) => FileAnalysisStore.binary(zincPath.toIO).get().map(_.getAnalysis)
         case None => Optional.empty[CompileAnalysis]
       }
     }
 
     val lookup = MockedLookup(analysisMap)
 
-    val store = fileAnalysisStore(ctx.dest / zincCache)
+    val store = FileAnalysisStore.binary((ctx.dest / zincFile).toIO)
 
     // Fix jdk classes marked as binary dependencies, see https://github.com/com-lihaoyi/mill/pull/1904
     val converter = MappedFileConverter.empty
@@ -595,7 +585,7 @@ class ZincWorkerImpl(
       setup = ic.setup(
         lookup = lookup,
         skip = false,
-        cacheFile = zincCache.toNIO,
+        cacheFile = zincFile.toNIO,
         cache = new FreshCompilerCache,
         incOptions = incOptions,
         reporter = newReporter,
@@ -639,7 +629,7 @@ class ZincWorkerImpl(
           newResult.setup()
         )
       )
-      Result.Success(CompilationResult((ctx.dest / zincCache), PathRef(classesDir)))
+      Result.Success(CompilationResult((ctx.dest / zincFile), PathRef(classesDir)))
     } catch {
       case e: CompileFailed =>
         Result.Failure(e.toString)