Bootstrapped pickling exception when pickling locally defined class.

[felixmulder]

From ZipArchive.scala:

for (zipEntry <- iter) {
  val dir = getDir(dirs, zipEntry)
  if (!zipEntry.isDirectory) {
    class FileEntry() extends Entry(zipEntry.getName) {
      override def lastModified = zipEntry.getTime()
      override def input        = resourceInputStream(path)
      override def sizeOption   = None
    }
    val f = new FileEntry()
    dir.entries(f.name) = f
  }
}

Pickling fails when bootstrapping this as part of the killing reflect io PR.

Message:

java.lang.AssertionError: assertion failed: unresolved symbols: class FileEntry when pickling /Users/fixel/Projects/dotty/compiler/src/dotty/tools/io/ZipArchive.scala
	at scala.Predef$.assert(Predef.scala:170)
	at dotty.tools.dotc.core.tasty.TreePickler.pickle(TreePickler.scala:608)
	at dotty.tools.dotc.transform.Pickler$$anonfun$run$2$$anonfun$apply$1.apply(Pickler.scala:51)
	at dotty.tools.dotc.transform.Pickler$$anonfun$run$2$$anonfun$apply$1.apply(Pickler.scala:44)
	at scala.collection.immutable.List.foreach(List.scala:392)
	at dotty.tools.dotc.transform.Pickler$$anonfun$run$2.apply(Pickler.scala:44)
	at dotty.tools.dotc.transform.Pickler$$anonfun$run$2.apply(Pickler.scala:43)
	at scala.collection.immutable.List.foreach(List.scala:392)
	at dotty.tools.dotc.transform.Pickler.run(Pickler.scala:43)
	at dotty.tools.dotc.core.Phases$Phase$$anonfun$runOn$1.apply(Phases.scala:283)
	at dotty.tools.dotc.core.Phases$Phase$$anonfun$runOn$1.apply(Phases.scala:281)
	at scala.collection.immutable.List.map(List.scala:288)
	at dotty.tools.dotc.core.Phases$Phase$class.runOn(Phases.scala:281)
	at dotty.tools.dotc.transform.Pickler.runOn(Pickler.scala:75)
	at dotty.tools.dotc.Run$$anonfun$compileUnits$1$$anonfun$apply$mcV$sp$1.apply(Run.scala:76)
	at dotty.tools.dotc.Run$$anonfun$compileUnits$1$$anonfun$apply$mcV$sp$1.apply(Run.scala:73)
	at scala.collection.IndexedSeqOptimized$class.foreach(IndexedSeqOptimized.scala:33)
	at scala.collection.mutable.ArrayOps$ofRef.foreach(ArrayOps.scala:186)
	at dotty.tools.dotc.Run$$anonfun$compileUnits$1.apply$mcV$sp(Run.scala:73)
	at dotty.tools.dotc.Run$$anonfun$compileUnits$1.apply(Run.scala:67)
	at dotty.tools.dotc.Run$$anonfun$compileUnits$1.apply(Run.scala:67)
	at dotty.tools.dotc.util.Stats$.monitorHeartBeat(Stats.scala:76)
	at dotty.tools.dotc.Run.compileUnits(Run.scala:67)
	at dotty.tools.dotc.Run.compileSources(Run.scala:64)
	at dotty.tools.dotc.Run.compile(Run.scala:48)
	at dotty.tools.dotc.Driver.doCompile(Driver.scala:26)
	at dotty.tools.dotc.Driver.process(Driver.scala:124)
	at xsbt.CachedCompilerImpl.run(CompilerInterface.scala:63)
	at xsbt.CachedCompilerImpl.run(CompilerInterface.scala:53)
	at xsbt.CompilerInterface.run(CompilerInterface.scala:37)
	at sun.reflect.GeneratedMethodAccessor22.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at sbt.compiler.AnalyzingCompiler.call(AnalyzingCompiler.scala:107)
	at sbt.compiler.AnalyzingCompiler.compile(AnalyzingCompiler.scala:53)
	at sbt.compiler.AnalyzingCompiler.compile(AnalyzingCompiler.scala:47)
	at sbt.compiler.MixedAnalyzingCompiler$$anonfun$compileScala$1$1.apply$mcV$sp(MixedAnalyzingCompiler.scala:50)

[odersky]

Can you make this into a self-contained test case? I tried to compile ZipArchive directly, but there were other incompatibilities which caused type errors.

[smarter]

Reproduction, alas not minimal: #3825

[allanrenucci]

Not sure it is the same issue, but this fails -Ytest-pickler on master:

sealed class Entry(path: Int)

class Test {
  def test = {
    class FileEntry() extends Entry(1)
    val f = new FileEntry()
  }
}

> dotc Test.scala -Ytest-pickler -Ystop-after:pickler
exception occurred while compiling Test.scala
Exception in thread "main" class dotty.tools.dotc.reporting.diagnostic.messages$Error at ?: pickling difference for class Entry in Test.scala, for details:
                   |
                   |  diff before-pickling.txt after-pickling.txt
	at dotty.tools.dotc.reporting.Reporting.error(Reporter.scala:88)
	at dotty.tools.dotc.reporting.Reporting.error$(Reporter.scala:87)
	at dotty.tools.dotc.core.Contexts$Context.error(Contexts.scala:68)
	at dotty.tools.dotc.transform.Pickler.testSame(Pickler.scala:107)
	at dotty.tools.dotc.transform.Pickler.$anonfun$testUnpickler$6(Pickler.scala:99)
	at dotty.tools.dotc.transform.Pickler.$anonfun$testUnpickler$6$adapted(Pickler.scala:97)
	at scala.collection.TraversableLike$WithFilter.$anonfun$foreach$1(TraversableLike.scala:789)
	at scala.collection.mutable.HashMap.$anonfun$foreach$1(HashMap.scala:138)
	at scala.collection.mutable.HashTable.foreachEntry(HashTable.scala:236)
	at scala.collection.mutable.HashTable.foreachEntry$(HashTable.scala:229)
	at scala.collection.mutable.HashMap.foreachEntry(HashMap.scala:40)
	at scala.collection.mutable.HashMap.foreach(HashMap.scala:138)
	at scala.collection.TraversableLike$WithFilter.foreach(TraversableLike.scala:788)
	at dotty.tools.dotc.transform.Pickler.testUnpickler(Pickler.scala:97)
	at dotty.tools.dotc.transform.Pickler.runOn(Pickler.scala:83)
	at dotty.tools.dotc.Run.$anonfun$compileUnits$3(Run.scala:125)
	at scala.runtime.java8.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.java:12)
	at dotty.tools.dotc.util.Stats$.trackTime(Stats.scala:47)
	at dotty.tools.dotc.Run.$anonfun$compileUnits$2(Run.scala:123)
	at dotty.tools.dotc.Run.$anonfun$compileUnits$2$adapted(Run.scala:121)
	at scala.collection.IndexedSeqOptimized.foreach(IndexedSeqOptimized.scala:32)
	at scala.collection.IndexedSeqOptimized.foreach$(IndexedSeqOptimized.scala:29)
	at scala.collection.mutable.ArrayOps$ofRef.foreach(ArrayOps.scala:191)
	at dotty.tools.dotc.Run.runPhases$1(Run.scala:121)
	at dotty.tools.dotc.Run.$anonfun$compileUnits$1(Run.scala:141)
	at scala.runtime.java8.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.java:12)
	at dotty.tools.dotc.util.Stats$.maybeMonitored(Stats.scala:88)
	at dotty.tools.dotc.Run.compileUnits(Run.scala:107)
	at dotty.tools.dotc.Run.compileSources(Run.scala:94)
	at dotty.tools.dotc.Run.compile(Run.scala:78)
	at dotty.tools.dotc.Driver.doCompile(Driver.scala:29)
	at dotty.tools.dotc.Driver.process(Driver.scala:127)
	at dotty.tools.dotc.Driver.process(Driver.scala:96)
	at dotty.tools.dotc.Driver.process(Driver.scala:108)
	at dotty.tools.dotc.Driver.main(Driver.scala:135)
	at dotty.tools.dotc.Main.main(Main.scala)
java.lang.RuntimeException: Nonzero exit code returned from runner: 1
	at scala.sys.package$.error(package.scala:27)

The annotation @scala.annotation.internal.Child[FileEntry]() is missing after pickling

[nicolasstucki]

@OlivierBlanvillain should have a look to that minimization. He has some experience and thoughts about sealed classes being extended by anonymous classes.