Project compiles in 18 seconds on scala 2, compilation never ends on scala 3 #19892

urieli · 2024-03-06T16:07:34Z

Compiler version

3.3.3 and 3.4.0

Minimized code

The project I'm attempting to compile is here.

git clone https://gitlab.com/joliciel/test-server.git
cd test-server
sbt

I removed the business modules (which compile quickly) and kept only the api module (whose compilation never ends).
I haven't minimized the code further as I could find no way of determining which parts were freezing the compiler.

Output

 % sbt
[info] welcome to sbt 1.9.9 (Eclipse Adoptium Java 17.0.2)
[info] loading global plugins from /home/assaf/.sbt/1.0/plugins
[info] loading settings for project test-server-build from plugins.sbt ...
[info] loading project definition from /home/assaf/javawork/jochre3/test-server/project
[info] loading settings for project jochre3-server from build.sbt ...
[warn] JOCHRE3_SERVER_VERSION env var not found
[info] set current project to jochre3-server (in build file:/home/assaf/javawork/jochre3/test-server/)
[info] sbt server started at local:///home/assaf/.sbt/1.0/server/92affff4cbf1ff9d4214/sock
[info] started sbt server
sbt:jochre3-server> clean
[success] Total time: 0 s, completed Mar 6, 2024, 4:02:19 PM
sbt:jochre3-server> compile
[info] compiling 22 Scala sources to /home/assaf/javawork/jochre3/test-server/modules/api/target/scala-2.13/classes ...
[warn] 1 deprecation
[warn] 1 deprecation (since 3.7.0)
[warn] 2 deprecations in total; re-run with -deprecation for details
[warn] three warnings found
[success] Total time: 18 s, completed Mar 6, 2024, 4:02:40 PM
sbt:jochre3-server> ++ 3.3.3
[info] Setting Scala version to 3.3.3 on 1 projects.
[info] Excluded 1 projects, run ++ 3.3.3 -v for more details.
[info] Reapplying settings...
[info] set current project to jochre3-server (in build file:/home/assaf/javawork/jochre3/test-server/)
sbt:jochre3-server> compile
[info] compiling 22 Scala sources to /home/assaf/javawork/jochre3/test-server/modules/api/target/scala-3.3.3/classes ...

  | => api / Compile / compileIncremental 3292s

Expectation

I would expect scala 3 to compile the code, which scala 2.13.13 compiles in 18 seconds, in a reasonable amount of time.

som-snytt · 2024-03-06T17:25:24Z

more annoyingly,

[warn] Canceling execution...
^C
[warn] Canceling execution...
^C
[warn] Canceling execution...
^C
[warn] Canceling execution...
^C
[warn] Canceling execution...
^C
[warn] Canceling execution...
^C
[warn] Canceling execution...
^C
[warn] Canceling execution...
^C
[warn] Canceling execution...

  | => api / Compile / compileIncremental 1567s

lrytz · 2024-03-06T18:40:22Z

Scala 2 PRs related to cancellation: scala/scala#6479, scala/scala#8448 [edit: is there a scala3 ticket already? should spin one off otherwise.]

WojciechMazur · 2024-03-11T16:29:41Z

Thread seems to be stuck in typer, might be related to #19907 (both use Tapir, but this project does. not use long list of server endpoint, instead might be coused by combination of 2 complex type systems coming from Tapir and ZIO

"pool-8-thread-4" #124 prio=5 os_prio=31 cpu=185732.93ms elapsed=242.73s tid=0x0000000168035a00 nid=0xe007 runnable  [0x00000002c90c1000]
   java.lang.Thread.State: RUNNABLE
        at java.lang.System.identityHashCode(java.base@17.0.7/Native Method)
        at dotty.tools.dotc.core.Types$BindingType.identityHash(Types.scala:2297)
        at dotty.tools.dotc.core.Types$BindingType.identityHash$(Types.scala:2286)
        at dotty.tools.dotc.core.Types$HKLambda.identityHash(Types.scala:3839)
        at dotty.tools.dotc.core.Types$ParamRef.computeHash(Types.scala:4697)
        at dotty.tools.dotc.core.Types$CachedProxyType.hash(Types.scala:2175)
        at dotty.tools.dotc.core.Hashable.typeHash(Hashable.scala:51)
        at dotty.tools.dotc.core.Hashable.typeHash$(Hashable.scala:42)
        at dotty.tools.dotc.core.Uniques$AppliedUniques.typeHash(Uniques.scala:66)
        at dotty.tools.dotc.core.Hashable.finishHash(Hashable.scala:72)
        at dotty.tools.dotc.core.Hashable.finishHash$(Hashable.scala:42)
        at dotty.tools.dotc.core.Uniques$AppliedUniques.finishHash(Uniques.scala:66)
        at dotty.tools.dotc.core.Hashable.finishHash(Hashable.scala:84)
        at dotty.tools.dotc.core.Hashable.finishHash$(Hashable.scala:42)
        at dotty.tools.dotc.core.Uniques$AppliedUniques.finishHash(Uniques.scala:66)
        at dotty.tools.dotc.core.Hashable.doHash(Hashable.scala:110)
        at dotty.tools.dotc.core.Hashable.doHash$(Hashable.scala:42)
        at dotty.tools.dotc.core.Uniques$AppliedUniques.doHash(Uniques.scala:66)
        at dotty.tools.dotc.core.Uniques$AppliedUniques.enterIfNew(Uniques.scala:70)
        at dotty.tools.dotc.core.Types$AppliedType$.apply(Types.scala:4672)
        at dotty.tools.dotc.core.TypeApplications$.appliedTo$extension(TypeApplications.scala:426)
        at dotty.tools.dotc.core.Types$AppliedType.derivedAppliedType(Types.scala:4646)
        at dotty.tools.dotc.core.Substituters$.subst(Substituters.scala:22)
        at dotty.tools.dotc.core.Types$Type.subst(Types.scala:1880)
        at dotty.tools.dotc.core.Types$HKTypeLambda.newLikeThis$$anonfun$4(Types.scala:4306)
        at dotty.tools.dotc.core.Types$HKTypeLambda$$Lambda$6301/0x0000000801131b68.apply(Unknown Source)
        at dotty.tools.dotc.core.Types$HKTypeLambda.<init>(Types.scala:4263)
        at dotty.tools.dotc.core.Types$HKTypeLambda$.apply(Types.scala:4370)
        at dotty.tools.dotc.core.Types$HKTypeLambda.newLikeThis(Types.scala:4306)
        at dotty.tools.dotc.core.Types$HKTypeLambda.newLikeThis(Types.scala:4301)
        at dotty.tools.dotc.core.Types$HKTypeLambda.newLikeThis(Types.scala:4300)
        at dotty.tools.dotc.core.Types$LambdaType.derivedLambdaType(Types.scala:3823)
        at dotty.tools.dotc.core.Types$LambdaType.derivedLambdaType$(Types.scala:3762)
        at dotty.tools.dotc.core.Types$HKLambda.derivedLambdaType(Types.scala:3839)
        at dotty.tools.dotc.core.Types$ApproximatingTypeMap.derivedLambdaType(Types.scala:6534)
        at dotty.tools.dotc.core.Types$TypeMap.mapOverLambda(Types.scala:6097)
        at dotty.tools.dotc.core.TypeOps$AsSeenFromMap.apply(TypeOps.scala:105)
        at dotty.tools.dotc.core.Types$TypeMap.op$proxy20$1(Types.scala:6127)
        at dotty.tools.dotc.core.Types$TypeMap.mapOver(Types.scala:6127)
        at dotty.tools.dotc.core.TypeOps$AsSeenFromMap.apply(TypeOps.scala:111)
        at dotty.tools.dotc.core.TypeOps$.asSeenFrom(TypeOps.scala:55)
        at dotty.tools.dotc.core.Types$Type.asSeenFrom(Types.scala:1091)
        at dotty.tools.dotc.core.Denotations$SingleDenotation.derived$1(Denotations.scala:1102)
        at dotty.tools.dotc.core.Denotations$SingleDenotation.computeAsSeenFrom(Denotations.scala:1129)
        at dotty.tools.dotc.core.Denotations$SingleDenotation.computeAsSeenFrom(Denotations.scala:1082)
        at dotty.tools.dotc.core.Denotations$PreDenotation.asSeenFrom(Denotations.scala:137)
        at dotty.tools.dotc.core.SymDenotations$ClassDenotation.findMember(SymDenotations.scala:2185)
        at dotty.tools.dotc.core.Types$Type.go$1(Types.scala:756)
        at dotty.tools.dotc.core.Types$Type.findMember(Types.scala:937)
        at dotty.tools.dotc.core.Types$Type.memberBasedOnFlags(Types.scala:729)
        at dotty.tools.dotc.core.Types$Type.nonPrivateMember(Types.scala:719)
        at dotty.tools.dotc.core.Types$NamedType.memberDenot(Types.scala:2553)
        at dotty.tools.dotc.core.Types$NamedType.memberDenot(Types.scala:2540)
        at dotty.tools.dotc.core.Types$NamedType.fromDesignator$1(Types.scala:2503)
        at dotty.tools.dotc.core.Types$NamedType.computeDenot(Types.scala:2518)
        at dotty.tools.dotc.core.Types$NamedType.denot(Types.scala:2475)
        at dotty.tools.dotc.core.Types$NamedType.info(Types.scala:2464)
        at dotty.tools.dotc.core.TypeApplications$.typeParams$extension(TypeApplications.scala:186)
        at dotty.tools.dotc.core.SymDenotations$ClassDenotation.computeApplied$1(SymDenotations.scala:2274)
        at dotty.tools.dotc.core.SymDenotations$ClassDenotation.recur$4(SymDenotations.scala:2282)
        at dotty.tools.dotc.core.SymDenotations$ClassDenotation.baseTypeOf(SymDenotations.scala:2345)
        at dotty.tools.dotc.core.Types$Type.baseType(Types.scala:1195)
        at dotty.tools.dotc.core.Types$NamedType.argForParam(Types.scala:2755)
        at dotty.tools.dotc.core.Types$ApproximatingTypeMap.expandParam(Types.scala:6339)
        at dotty.tools.dotc.core.Types$ApproximatingTypeMap.derivedSelect(Types.scala:6357)
        at dotty.tools.dotc.core.TypeOps$AsSeenFromMap.apply(TypeOps.scala:103)
        at dotty.tools.dotc.core.Types$TypeMap.op$proxy18$1(Types.scala:6080)
        at dotty.tools.dotc.core.Types$TypeMap.mapArg(Types.scala:6080)
        at dotty.tools.dotc.core.Types$TypeMap.mapArgs(Types.scala:6084)
        at dotty.tools.dotc.core.Types$TypeMap.mapOver(Types.scala:6121)
        at dotty.tools.dotc.core.TypeOps$AsSeenFromMap.apply(TypeOps.scala:111)
        at dotty.tools.dotc.core.Types$TypeMap.mapOverLambda(Types.scala:6097)
        at dotty.tools.dotc.core.TypeOps$AsSeenFromMap.apply(TypeOps.scala:105)
        at dotty.tools.dotc.core.Types$TypeMap.op$proxy20$1(Types.scala:6127)
        at dotty.tools.dotc.core.Types$TypeMap.mapOver(Types.scala:6127)
        at dotty.tools.dotc.core.TypeOps$AsSeenFromMap.apply(TypeOps.scala:111)
        at dotty.tools.dotc.core.TypeOps$.asSeenFrom(TypeOps.scala:55)
        at dotty.tools.dotc.core.Types$Type.asSeenFrom(Types.scala:1091)
        at dotty.tools.dotc.core.Denotations$SingleDenotation.derived$1(Denotations.scala:1102)
        at dotty.tools.dotc.core.Denotations$SingleDenotation.computeAsSeenFrom(Denotations.scala:1129)
        at dotty.tools.dotc.core.Denotations$SingleDenotation.computeAsSeenFrom(Denotations.scala:1082)
        at dotty.tools.dotc.core.Denotations$PreDenotation.asSeenFrom(Denotations.scala:137)
        at dotty.tools.dotc.core.SymDenotations$ClassDenotation.findMember(SymDenotations.scala:2185)
        at dotty.tools.dotc.core.Types$Type.go$1(Types.scala:756)
        at dotty.tools.dotc.core.Types$Type.findMember(Types.scala:937)
        at dotty.tools.dotc.core.Types$Type.memberBasedOnFlags(Types.scala:729)
        at dotty.tools.dotc.core.Types$Type.nonPrivateMember(Types.scala:719)
        at dotty.tools.dotc.core.Types$NamedType.memberDenot(Types.scala:2553)
        at dotty.tools.dotc.core.Types$NamedType.memberDenot(Types.scala:2540)
        at dotty.tools.dotc.core.Types$NamedType.fromDesignator$1(Types.scala:2503)
        at dotty.tools.dotc.core.Types$NamedType.computeDenot(Types.scala:2518)
        at dotty.tools.dotc.core.Types$NamedType.denot(Types.scala:2475)
        at dotty.tools.dotc.core.Types$NamedType.info(Types.scala:2464)
        at dotty.tools.dotc.core.Types$TypeRef.underlying(Types.scala:3024)
        at dotty.tools.dotc.core.Types$TypeProxy.superType(Types.scala:2132)
        at dotty.tools.dotc.core.Types$AppliedType.superType(Types.scala:4556)
        at dotty.tools.dotc.core.SymDenotations$ClassDenotation.computeApplied$1(SymDenotations.scala:2276)
        at dotty.tools.dotc.core.SymDenotations$ClassDenotation.recur$4(SymDenotations.scala:2282)
        at dotty.tools.dotc.core.SymDenotations$ClassDenotation.baseTypeOf(SymDenotations.scala:2345)
        at dotty.tools.dotc.core.Types$Type.baseType(Types.scala:1195)
        at dotty.tools.dotc.core.TypeOps$AsSeenFromMap.toPrefix$1(TypeOps.scala:83)
        at dotty.tools.dotc.core.TypeOps$AsSeenFromMap.apply(TypeOps.scala:107)
        at dotty.tools.dotc.core.TypeOps$AsSeenFromMap.op$proxy2$1(TypeOps.scala:103)
        at dotty.tools.dotc.core.TypeOps$AsSeenFromMap.apply(TypeOps.scala:103)
        at dotty.tools.dotc.core.Types$TypeMap.op$proxy18$1(Types.scala:6080)
        at dotty.tools.dotc.core.Types$TypeMap.mapArg(Types.scala:6080)
        at dotty.tools.dotc.core.Types$TypeMap.mapArgs(Types.scala:6084)
        at dotty.tools.dotc.core.Types$TypeMap.mapArgs(Types.scala:6085)
        at dotty.tools.dotc.core.Types$TypeMap.mapArgs(Types.scala:6085)
        at dotty.tools.dotc.core.Types$TypeMap.mapOver(Types.scala:6121)
        at dotty.tools.dotc.core.TypeOps$AsSeenFromMap.apply(TypeOps.scala:111)
        at dotty.tools.dotc.core.Types$TypeMap.mapOverLambda(Types.scala:6097)
        at dotty.tools.dotc.core.TypeOps$AsSeenFromMap.apply(TypeOps.scala:105)
        at dotty.tools.dotc.core.Types$TypeMap.op$proxy20$1(Types.scala:6127)
        at dotty.tools.dotc.core.Types$TypeMap.mapOver(Types.scala:6127)
        at dotty.tools.dotc.core.TypeOps$AsSeenFromMap.apply(TypeOps.scala:111)
        at dotty.tools.dotc.core.TypeOps$.asSeenFrom(TypeOps.scala:55)
        at dotty.tools.dotc.core.Types$Type.asSeenFrom(Types.scala:1091)
        at dotty.tools.dotc.core.Denotations$SingleDenotation.derived$1(Denotations.scala:1102)
        at dotty.tools.dotc.core.Denotations$SingleDenotation.computeAsSeenFrom(Denotations.scala:1129)
        at dotty.tools.dotc.core.Denotations$SingleDenotation.computeAsSeenFrom(Denotations.scala:1082)
        at dotty.tools.dotc.core.Denotations$PreDenotation.asSeenFrom(Denotations.scala:137)
        at dotty.tools.dotc.core.SymDenotations$ClassDenotation.findMember(SymDenotations.scala:2185)
        at dotty.tools.dotc.core.Types$Type.go$1(Types.scala:756)
        at dotty.tools.dotc.core.Types$Type.findMember(Types.scala:937)
        at dotty.tools.dotc.core.Types$Type.memberBasedOnFlags(Types.scala:729)
        at dotty.tools.dotc.core.Types$Type.nonPrivateMember(Types.scala:719)
        at dotty.tools.dotc.core.Types$NamedType.memberDenot(Types.scala:2553)
        at dotty.tools.dotc.core.Types$NamedType.memberDenot(Types.scala:2540)
        at dotty.tools.dotc.core.Types$NamedType.fromDesignator$1(Types.scala:2503)
        at dotty.tools.dotc.core.Types$NamedType.computeDenot(Types.scala:2518)
        at dotty.tools.dotc.core.Types$NamedType.denot(Types.scala:2475)
        at dotty.tools.dotc.core.Types$NamedType.info(Types.scala:2464)
        at dotty.tools.dotc.core.Types$TermLambda.dotty$tools$dotc$core$Types$TermLambda$$_$compute$1(Types.scala:3979)
        at dotty.tools.dotc.core.Types$TermLambda.dotty$tools$dotc$core$Types$TermLambda$$_$compute$1(Types.scala:3986)
        at dotty.tools.dotc.core.Types$TermLambda.applyPrefix$1(Types.scala:3974)
        at dotty.tools.dotc.core.Types$TermLambda.dotty$tools$dotc$core$Types$TermLambda$$_$compute$1(Types.scala:3978)
        at dotty.tools.dotc.core.Types$TermLambda.dotty$tools$dotc$core$Types$TermLambda$$_$compute$1(Types.scala:3986)
        at dotty.tools.dotc.core.Types$TermLambda$DepAcc$1.apply(Types.scala:3965)
        at dotty.tools.dotc.core.Types$TermLambda$DepAcc$1.apply(Types.scala:3965)
        at dotty.tools.dotc.core.Types$TypeAccumulator.foldOver(Types.scala:6608)
        at dotty.tools.dotc.core.Types$TermLambda.dotty$tools$dotc$core$Types$TermLambda$$_$compute$1(Types.scala:4005)
        at dotty.tools.dotc.core.Types$TermLambda.dotty$tools$dotc$core$Types$TermLambda$$depStatus(Types.scala:4006)
        at dotty.tools.dotc.core.Types$TermLambda.dependencyStatus(Types.scala:4020)
        at dotty.tools.dotc.core.Types$TermLambda.resultType(Types.scala:3944)
        at dotty.tools.dotc.core.Types$TermLambda.resultType$(Types.scala:3936)
        at dotty.tools.dotc.core.Types$MethodType.resultType(Types.scala:4081)
        at dotty.tools.dotc.core.Types$MethodOrPoly.computeSignature$2(Types.scala:3875)
        at dotty.tools.dotc.core.Types$MethodOrPoly.signature(Types.scala:3905)
        at dotty.tools.dotc.core.Types$MethodOrPoly.computeSignature$2(Types.scala:3876)
        at dotty.tools.dotc.core.Types$MethodOrPoly.signature(Types.scala:3905)
        at dotty.tools.dotc.core.Denotations$SingleDenotation.signature(Denotations.scala:623)
        at dotty.tools.dotc.core.Denotations$SingleDenotation.signature(Denotations.scala:613)
        at dotty.tools.dotc.core.Denotations$SingleDenotation.atSignature(Denotations.scala:654)
        at dotty.tools.dotc.core.Denotations$SingleDenotation.atSignature(Denotations.scala:650)
        at dotty.tools.dotc.core.Denotations$MultiDenotation.atSignature(Denotations.scala:1262)
        at dotty.tools.dotc.core.Types$NamedType.disambiguate(Types.scala:2529)
        at dotty.tools.dotc.core.Types$NamedType.disambiguate(Types.scala:2525)
        at dotty.tools.dotc.core.Types$NamedType.memberDenot(Types.scala:2548)
        at dotty.tools.dotc.core.Types$NamedType.fromDesignator$1(Types.scala:2503)
        at dotty.tools.dotc.core.Types$NamedType.computeDenot(Types.scala:2518)
        at dotty.tools.dotc.core.Types$NamedType.denot(Types.scala:2475)
        at dotty.tools.dotc.core.Types$TermRef.isOverloaded(Types.scala:2957)
        at dotty.tools.dotc.core.Types$Type.widenSingleton(Types.scala:1300)
        at dotty.tools.dotc.typer.ProtoTypes$Compatibility.normalizedCompatible(ProtoTypes.scala:64)
        at dotty.tools.dotc.typer.ProtoTypes$Compatibility.normalizedCompatible$(ProtoTypes.scala:31)
        at dotty.tools.dotc.typer.Typer.normalizedCompatible(Typer.scala:120)
        at dotty.tools.dotc.typer.ProtoTypes$SelectionProto.qualifies$1(ProtoTypes.scala:227)
        at dotty.tools.dotc.typer.ProtoTypes$SelectionProto.isMatchedBy$$anonfun$1(ProtoTypes.scala:230)
        at dotty.tools.dotc.typer.ProtoTypes$SelectionProto$$Lambda$5933/0x0000000801096ed8.apply(Unknown Source)
        at dotty.tools.dotc.core.Denotations$SingleDenotation.hasAltWith(Denotations.scala:645)
        at dotty.tools.dotc.core.Denotations$MultiDenotation.hasAltWith(Denotations.scala:1282)
        at dotty.tools.dotc.typer.ProtoTypes$SelectionProto.isMatchedBy(ProtoTypes.scala:230)
        at dotty.tools.dotc.core.TypeComparer.isMatchedByProto(TypeComparer.scala:2145)
        at dotty.tools.dotc.core.TypeComparer.firstTry$1(TypeComparer.scala:345)
        at dotty.tools.dotc.core.TypeComparer.recur(TypeComparer.scala:1553)
        at dotty.tools.dotc.core.TypeComparer.isSubType(TypeComparer.scala:214)
        at dotty.tools.dotc.core.TypeComparer.isSubType(TypeComparer.scala:224)
        at dotty.tools.dotc.core.TypeComparer.topLevelSubType(TypeComparer.scala:132)
        at dotty.tools.dotc.core.TypeComparer.testSubType(TypeComparer.scala:149)
        at dotty.tools.dotc.core.TypeComparer$.testSubType(TypeComparer.scala:3159)
        at dotty.tools.dotc.typer.Typer.adaptNoArgsOther$1(Typer.scala:4090)
        at dotty.tools.dotc.typer.Typer.adaptNoArgs$1(Typer.scala:4177)
        at dotty.tools.dotc.typer.Typer.adapt1(Typer.scala:4406)
        at dotty.tools.dotc.typer.Typer.adapt(Typer.scala:3697)
        at dotty.tools.dotc.typer.Typer.readapt$1(Typer.scala:3709)
        at dotty.tools.dotc.typer.Typer.readaptSimplified$1(Typer.scala:3710)
        at dotty.tools.dotc.typer.Typer.addImplicitArgs$1(Typer.scala:3942)
        at dotty.tools.dotc.typer.Typer.adaptNoArgsImplicitMethod$1(Typer.scala:3951)
        at dotty.tools.dotc.typer.Typer.adaptNoArgs$1(Typer.scala:4153)
        at dotty.tools.dotc.typer.Typer.adapt1(Typer.scala:4406)
        at dotty.tools.dotc.typer.Typer.adapt(Typer.scala:3697)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3293)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3297)
        at dotty.tools.dotc.typer.Typer.typedExpr(Typer.scala:3408)
        at dotty.tools.dotc.typer.Typer.typeSelectOnTerm$1(Typer.scala:767)
        at dotty.tools.dotc.typer.Typer.typedSelect(Typer.scala:805)
        at dotty.tools.dotc.typer.Typer.typedNamed$1(Typer.scala:3107)
        at dotty.tools.dotc.typer.Typer.typedUnadapted(Typer.scala:3215)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3293)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3297)
        at dotty.tools.dotc.typer.Typer.typedExpr(Typer.scala:3408)
        at dotty.tools.dotc.typer.Applications.realApply$1(Applications.scala:957)
        at dotty.tools.dotc.typer.Applications.typedApply(Applications.scala:1117)
        at dotty.tools.dotc.typer.Applications.typedApply$(Applications.scala:351)
        at dotty.tools.dotc.typer.Typer.typedApply(Typer.scala:120)
        at dotty.tools.dotc.typer.Typer.typedUnnamed$1(Typer.scala:3132)
        at dotty.tools.dotc.typer.Typer.typedUnadapted(Typer.scala:3216)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3293)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3297)
        at dotty.tools.dotc.typer.Typer.typedExpr(Typer.scala:3408)
        at dotty.tools.dotc.typer.Typer.typeSelectOnTerm$1(Typer.scala:767)
        at dotty.tools.dotc.typer.Typer.typedSelect(Typer.scala:805)
        at dotty.tools.dotc.typer.Typer.typedNamed$1(Typer.scala:3107)
        at dotty.tools.dotc.typer.Typer.typedUnadapted(Typer.scala:3215)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3293)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3297)
        at dotty.tools.dotc.typer.Typer.typedExpr(Typer.scala:3408)
        at dotty.tools.dotc.typer.Applications.realApply$1(Applications.scala:957)
        at dotty.tools.dotc.typer.Applications.typedApply(Applications.scala:1117)
        at dotty.tools.dotc.typer.Applications.typedApply$(Applications.scala:351)
        at dotty.tools.dotc.typer.Typer.typedApply(Typer.scala:120)
        at dotty.tools.dotc.typer.Typer.typedUnnamed$1(Typer.scala:3132)
        at dotty.tools.dotc.typer.Typer.typedUnadapted(Typer.scala:3216)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3293)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3297)
        at dotty.tools.dotc.typer.Typer.typedExpr(Typer.scala:3408)
        at dotty.tools.dotc.typer.Typer.typeSelectOnTerm$1(Typer.scala:767)
        at dotty.tools.dotc.typer.Typer.typedSelect(Typer.scala:805)
        at dotty.tools.dotc.typer.Typer.typedNamed$1(Typer.scala:3107)
        at dotty.tools.dotc.typer.Typer.typedUnadapted(Typer.scala:3215)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3293)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3297)
        at dotty.tools.dotc.typer.Typer.typedExpr(Typer.scala:3408)
        at dotty.tools.dotc.typer.Applications.realApply$1(Applications.scala:957)
        at dotty.tools.dotc.typer.Applications.typedApply(Applications.scala:1117)
        at dotty.tools.dotc.typer.Applications.typedApply$(Applications.scala:351)
        at dotty.tools.dotc.typer.Typer.typedApply(Typer.scala:120)
        at dotty.tools.dotc.typer.Typer.typedUnnamed$1(Typer.scala:3132)
        at dotty.tools.dotc.typer.Typer.typedUnadapted(Typer.scala:3216)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3293)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3297)
        at dotty.tools.dotc.typer.Typer.typedExpr(Typer.scala:3408)
        at dotty.tools.dotc.typer.Typer.typeSelectOnTerm$1(Typer.scala:767)
        at dotty.tools.dotc.typer.Typer.typedSelect(Typer.scala:805)
        at dotty.tools.dotc.typer.Typer.typedNamed$1(Typer.scala:3107)
        at dotty.tools.dotc.typer.Typer.typedUnadapted(Typer.scala:3215)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3293)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3297)
        at dotty.tools.dotc.typer.Typer.typedExpr(Typer.scala:3408)
        at dotty.tools.dotc.typer.Applications.realApply$1(Applications.scala:957)
        at dotty.tools.dotc.typer.Applications.typedApply(Applications.scala:1117)
        at dotty.tools.dotc.typer.Applications.typedApply$(Applications.scala:351)
        at dotty.tools.dotc.typer.Typer.typedApply(Typer.scala:120)
        at dotty.tools.dotc.typer.Typer.typedUnnamed$1(Typer.scala:3132)
        at dotty.tools.dotc.typer.Typer.typedUnadapted(Typer.scala:3216)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3293)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3297)
        at dotty.tools.dotc.typer.Typer.typedExpr(Typer.scala:3408)
        at dotty.tools.dotc.typer.Typer.typeSelectOnTerm$1(Typer.scala:767)
        at dotty.tools.dotc.typer.Typer.typedSelect(Typer.scala:805)
        at dotty.tools.dotc.typer.Typer.typedNamed$1(Typer.scala:3107)
        at dotty.tools.dotc.typer.Typer.typedUnadapted(Typer.scala:3215)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3293)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3297)
        at dotty.tools.dotc.typer.Typer.typedExpr(Typer.scala:3408)
        at dotty.tools.dotc.typer.Applications.realApply$1(Applications.scala:957)
        at dotty.tools.dotc.typer.Applications.typedApply(Applications.scala:1117)
        at dotty.tools.dotc.typer.Applications.typedApply$(Applications.scala:351)
        at dotty.tools.dotc.typer.Typer.typedApply(Typer.scala:120)
        at dotty.tools.dotc.typer.Typer.typedUnnamed$1(Typer.scala:3132)
        at dotty.tools.dotc.typer.Typer.typedUnadapted(Typer.scala:3216)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3293)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3297)
        at dotty.tools.dotc.typer.Typer.typedExpr(Typer.scala:3408)
        at dotty.tools.dotc.typer.Typer.typedValDef(Typer.scala:2552)
        at dotty.tools.dotc.typer.Typer.typedNamed$1(Typer.scala:3111)
        at dotty.tools.dotc.typer.Typer.typedUnadapted(Typer.scala:3215)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3293)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3297)
        at dotty.tools.dotc.typer.Typer.traverse$1(Typer.scala:3319)
        at dotty.tools.dotc.typer.Typer.typedStats(Typer.scala:3365)
        at dotty.tools.dotc.typer.Typer.typedClassDef(Typer.scala:2809)
        at dotty.tools.dotc.typer.Typer.typedTypeOrClassDef$1(Typer.scala:3120)
        at dotty.tools.dotc.typer.Typer.typedNamed$1(Typer.scala:3124)
        at dotty.tools.dotc.typer.Typer.typedUnadapted(Typer.scala:3215)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3293)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3297)
        at dotty.tools.dotc.typer.Typer.traverse$1(Typer.scala:3319)
        at dotty.tools.dotc.typer.Typer.typedStats(Typer.scala:3365)
        at dotty.tools.dotc.typer.Typer.typedPackageDef(Typer.scala:2942)
        at dotty.tools.dotc.typer.Typer.typedUnnamed$1(Typer.scala:3166)
        at dotty.tools.dotc.typer.Typer.typedUnadapted(Typer.scala:3216)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3293)
        at dotty.tools.dotc.typer.Typer.typed(Typer.scala:3297)
        at dotty.tools.dotc.typer.Typer.typedExpr(Typer.scala:3408)
        at dotty.tools.dotc.typer.TyperPhase.typeCheck$$anonfun$1(TyperPhase.scala:47)
        at dotty.tools.dotc.typer.TyperPhase$$Lambda$5931/0x000000080108dc78.applyVoid(Unknown Source)
        at scala.runtime.function.JProcedure1.apply(JProcedure1.java:15)
        at scala.runtime.function.JProcedure1.apply(JProcedure1.java:10)
        at dotty.tools.dotc.core.Phases$Phase.monitor(Phases.scala:480)
        at dotty.tools.dotc.typer.TyperPhase.typeCheck(TyperPhase.scala:53)
        at dotty.tools.dotc.typer.TyperPhase.$anonfun$4(TyperPhase.scala:99)
        at dotty.tools.dotc.typer.TyperPhase$$Lambda$5929/0x000000080108d4e0.apply(Unknown Source)
        at scala.collection.Iterator$$anon$6.hasNext(Iterator.scala:479)
        at scala.collection.Iterator$$anon$9.hasNext(Iterator.scala:583)
        at scala.collection.immutable.List.prependedAll(List.scala:155)
        at scala.collection.immutable.List$.from(List.scala:684)
        at scala.collection.immutable.List$.from(List.scala:681)
        at scala.collection.IterableOps$WithFilter.map(Iterable.scala:898)
        at dotty.tools.dotc.typer.TyperPhase.runOn(TyperPhase.scala:100)
        at dotty.tools.dotc.Run.runPhases$1$$anonfun$1(Run.scala:315)
        at dotty.tools.dotc.Run$$Lambda$5742/0x0000000801014208.applyVoid(Unknown Source)
        at scala.runtime.function.JProcedure1.apply(JProcedure1.java:15)
        at scala.runtime.function.JProcedure1.apply(JProcedure1.java:10)
        at scala.collection.ArrayOps$.foreach$extension(ArrayOps.scala:1323)
        at dotty.tools.dotc.Run.runPhases$1(Run.scala:337)
        at dotty.tools.dotc.Run.compileUnits$$anonfun$1(Run.scala:350)
        at dotty.tools.dotc.Run.compileUnits$$anonfun$adapted$1(Run.scala:360)
        at dotty.tools.dotc.Run$$Lambda$5696/0x0000000800fdc568.apply(Unknown Source)
        at dotty.tools.dotc.util.Stats$.maybeMonitored(Stats.scala:69)
        at dotty.tools.dotc.Run.compileUnits(Run.scala:360)
        at dotty.tools.dotc.Run.compileSources(Run.scala:261)
        at dotty.tools.dotc.Run.compile(Run.scala:246)
        at dotty.tools.dotc.Driver.doCompile(Driver.scala:37)
        at dotty.tools.xsbt.CompilerBridgeDriver.run(CompilerBridgeDriver.java:141)
        - locked <0x0000000404e362a8> (a dotty.tools.xsbt.CompilerBridgeDriver)
        at dotty.tools.xsbt.CompilerBridge.run(CompilerBridge.java:22)
        at sbt.internal.inc.AnalyzingCompiler.compile(AnalyzingCompiler.scala:91)
        at sbt.internal.inc.MixedAnalyzingCompiler.$anonfun$compile$7(MixedAnalyzingCompiler.scala:193)
        at sbt.internal.inc.MixedAnalyzingCompiler$$Lambda$5411/0x0000000800d7e688.apply$mcV$sp(Unknown Source)
        at scala.runtime.java8.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.java:23)
        at sbt.internal.inc.MixedAnalyzingCompiler.timed(MixedAnalyzingCompiler.scala:248)
        at sbt.internal.inc.MixedAnalyzingCompiler.$anonfun$compile$4(MixedAnalyzingCompiler.scala:183)
        at sbt.internal.inc.MixedAnalyzingCompiler.$anonfun$compile$4$adapted(MixedAnalyzingCompiler.scala:163)
        at sbt.internal.inc.MixedAnalyzingCompiler$$Lambda$5407/0x0000000800d7d718.apply(Unknown Source)
        at sbt.internal.inc.JarUtils$.withPreviousJar(JarUtils.scala:239)
        at sbt.internal.inc.MixedAnalyzingCompiler.compileScala$1(MixedAnalyzingCompiler.scala:163)
        at sbt.internal.inc.MixedAnalyzingCompiler.compile(MixedAnalyzingCompiler.scala:211)
        at sbt.internal.inc.IncrementalCompilerImpl.$anonfun$compileInternal$1(IncrementalCompilerImpl.scala:534)
        at sbt.internal.inc.IncrementalCompilerImpl.$anonfun$compileInternal$1$adapted(IncrementalCompilerImpl.scala:534)
        at sbt.internal.inc.IncrementalCompilerImpl$$Lambda$3289/0x00000008009f7c38.apply(Unknown Source)
        at sbt.internal.inc.Incremental$.$anonfun$apply$5(Incremental.scala:180)
        at sbt.internal.inc.Incremental$.$anonfun$apply$5$adapted(Incremental.scala:178)
        at sbt.internal.inc.Incremental$$$Lambda$3296/0x00000008009f9fd8.apply(Unknown Source)
        at sbt.internal.inc.Incremental$$anon$2.run(Incremental.scala:464)
        at sbt.internal.inc.IncrementalCommon$CycleState.next(IncrementalCommon.scala:116)
        at sbt.internal.inc.IncrementalCommon$$anon$1.next(IncrementalCommon.scala:56)
        at sbt.internal.inc.IncrementalCommon$$anon$1.next(IncrementalCommon.scala:52)
        at sbt.internal.inc.IncrementalCommon.cycle(IncrementalCommon.scala:263)
        at sbt.internal.inc.Incremental$.$anonfun$incrementalCompile$8(Incremental.scala:419)
        at sbt.internal.inc.Incremental$$$Lambda$3333/0x0000000800a0d800.apply(Unknown Source)
        at sbt.internal.inc.Incremental$.withClassfileManager(Incremental.scala:506)
        at sbt.internal.inc.Incremental$.incrementalCompile(Incremental.scala:406)
        at sbt.internal.inc.Incremental$.apply(Incremental.scala:172)
        at sbt.internal.inc.IncrementalCompilerImpl.compileInternal(IncrementalCompilerImpl.scala:534)
        at sbt.internal.inc.IncrementalCompilerImpl.$anonfun$compileIncrementally$1(IncrementalCompilerImpl.scala:488)
        at sbt.internal.inc.IncrementalCompilerImpl$$Lambda$3194/0x00000008009b95d8.apply(Unknown Source)
        at sbt.internal.inc.IncrementalCompilerImpl.handleCompilationError(IncrementalCompilerImpl.scala:332)
        at sbt.internal.inc.IncrementalCompilerImpl.compileIncrementally(IncrementalCompilerImpl.scala:425)
        at sbt.internal.inc.IncrementalCompilerImpl.compile(IncrementalCompilerImpl.scala:137)
        at sbt.Defaults$.compileIncrementalTaskImpl(Defaults.scala:2371)
        at sbt.Defaults$.$anonfun$compileIncrementalTask$2(Defaults.scala:2321)
        at sbt.Defaults$$$Lambda$3187/0x00000008009aaf98.apply(Unknown Source)
        at sbt.internal.server.BspCompileTask$.$anonfun$compute$1(BspCompileTask.scala:31)
        at sbt.internal.server.BspCompileTask$$$Lambda$3189/0x00000008009b7b08.apply(Unknown Source)
        at sbt.internal.io.Retry$.apply(Retry.scala:47)
        at sbt.internal.io.Retry$.apply(Retry.scala:29)
        at sbt.internal.io.Retry$.apply(Retry.scala:24)
        at sbt.internal.server.BspCompileTask$.compute(BspCompileTask.scala:31)
        at sbt.Defaults$.$anonfun$compileIncrementalTask$1(Defaults.scala:2319)
        at sbt.Defaults$$$Lambda$840/0x0000000800522c50.apply(Unknown Source)
        at scala.Function1.$anonfun$compose$1(Function1.scala:49)
        at scala.Function1$$Lambda$350/0x00000008003577e0.apply(Unknown Source)
        at sbt.internal.util.$tilde$greater.$anonfun$$u2219$1(TypeFunctions.scala:63)
        at sbt.internal.util.$tilde$greater$$Lambda$2781/0x00000008008f9640.apply(Unknown Source)
        at sbt.std.Transform$$anon$4.work(Transform.scala:69)
        at sbt.Execute.$anonfun$submit$2(Execute.scala:283)
        at sbt.Execute$$Lambda$2807/0x0000000800904508.apply(Unknown Source)
        at sbt.internal.util.ErrorHandling$.wideConvert(ErrorHandling.scala:24)
        at sbt.Execute.work(Execute.scala:292)
        at sbt.Execute.$anonfun$submit$1(Execute.scala:283)
        at sbt.Execute$$Lambda$2791/0x00000008008fc6c8.apply(Unknown Source)
        at sbt.ConcurrentRestrictions$$anon$4.$anonfun$submitValid$1(ConcurrentRestrictions.scala:265)
        at sbt.ConcurrentRestrictions$$anon$4$$Lambda$2802/0x00000008008fe890.apply(Unknown Source)
        at sbt.CompletionService$$anon$2.call(CompletionService.scala:65)
        at java.util.concurrent.FutureTask.run(java.base@17.0.7/FutureTask.java:264)
        at java.util.concurrent.Executors$RunnableAdapter.call(java.base@17.0.7/Executors.java:539)
        at java.util.concurrent.FutureTask.run(java.base@17.0.7/FutureTask.java:264)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(java.base@17.0.7/ThreadPoolExecutor.java:1136)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(java.base@17.0.7/ThreadPoolExecutor.java:635)
        at java.lang.Thread.run(java.base@17.0.7/Thread.java:833)

When working on minimization for the issue mentioned above, I'll try to minimize this one as well.

WojciechMazur · 2024-03-11T16:34:42Z

Also based on draft of #19897 I was able to track the def that takes long to typecheck

val postBatchEndpoint: ZPartialServerEndpoint[Requirements, String, ValidToken, (ProjectCode, BatchRequest), HttpError, BatchResponse, Any] = ???

WojciechMazur · 2024-03-11T23:50:29Z

The R parameter in def basicEndpoint[R] is inferred based on whole chain of method out invocations. The workaround to make compilation finish quickly is to hint the compiler about the type R

Self contained minimisation of issue:

abstract class ZPartialServerEndpoint[R, A, B, I, E, O, -C]
    extends EndpointOps[A, I, E, O, C]{
  override type ThisType[-_R] = ZPartialServerEndpoint[R, A, B, I, E, O, _R]
  override type EndpointType[_A, _I, _E, _O, -_R] =ZPartialServerEndpoint[R, _A, B, _I, _E, _O, _R]
}

trait EndpointOps[A, I, E, O, -R] {
  type EndpointType[_A, _I, _E, _O, -_R]
  type ThisType[-_R]
  def out[T]: EndpointType[A, I, E, T, R]
  def description(d: String): ThisType[R]
}

object Test {
  def basicEndpoint[R](): ZPartialServerEndpoint[R, Any, Any, Unit, Any, Unit, Any] = ???

  // commonts next to `.out[Any]` contain information about compilation time when chaining up to N `out` functions
  val case1 =
     basicEndpoint() // 1.5s
        .out[Any] // 1.6s
        .out[Any] // 1.7s
        .out[Any] // 2s
        .out[Any] // 4s
        .out[Any] // 33s
        .out[Any] // aborted after 5 min

  val case1Workaround =
    basicEndpoint[Any]() // 1.4s
      .out[Any] // 1.4s
      .out[Any] // 1.4s
      .out[Any] // 1.4s
      .out[Any] // 1.4s
      .out[Any] // 1.4s
      .out[Any] // 1.4s

  val case2_referToThisType =
    basicEndpoint()
      .out[Any] // 1.6s
      .out[Any] // 2.2s
      .out[Any] // 5.6s
      .out[Any] // 53s
      .description("Comment out to make compilation eventually finish")

  val case2Workaround =
    basicEndpoint[Any]()
      .out[Any] // 1.6s
      .out[Any] // 1.6s
      .out[Any] // 1.6s
      .out[Any] // 1.6s
      .description("Comment out to make compilation finish") // 1.6s
}

@Gedochao I suggest to move this issue to P1 similarly as other slow typer issue mentioned above
@odersky @noti0na1 I'm initially assigning this issue to you as it is in the same area as the previous type-inference related bug

noti0na1 · 2024-03-12T15:09:03Z

abstract class ZPartialServerEndpoint[R, A, B, I, E, O, -C]

It seems the number of type parameter does affect the performance. I reduce the number of type parameters of ZPartialServerEndpoint to 3, only including the necessary types used by basicEndpoint, out and description. The 30-second compilations become 4s.

abstract class Z[R, O, -C]
    extends EndpointOps[O, C]{
  override type ThisType[-_R] = Z[R, O, _R]
  override type EndpointType[_O, -_R] =Z[R, _O, _R]
}

trait EndpointOps[O, -R] {
  type EndpointType[_O, -_R]
  type ThisType[-_R]
  def out[T]: EndpointType[T, R]
  def description(d: String): ThisType[R]
}

object Test {
  def basicEndpoint[R](): Z[R, Unit, Any] = ???

  ...
}

Projections P # X are types that we would like to avoid. If X is a class type, there's nothing we can do. If X is an abstract type, we use skolemization and rewrite to (x?: P).X. If X is an alias type we should simply dealias but this was not done before. This caused an exonential blowup in scala#19892, where we costructed types of the form ZPartialServerEndpoint[R, A, B, I, E, O, -C] # EndpointType[A, I, E, T, R] ... # EndpointType[A, I, E, T, R] When the were 5 or more such selections, sompile times blew up (33s for 5, timeout after 5 minutes for 6). I am still not qute sure where the blowup happened. Looking at stacktraces of random interrups it seemed to be in a deep recursion of memberDenot and asSeenFrom calls.I believe it would still be interesting to find out more about this, in case there are other similar situations where combinations of deep projections with wide applications cannot be avoided. But for this precise problem, eagerly dealising fixes it.

odersky · 2024-03-12T16:06:41Z

Thanks for the minimizations! I turned lots of logging on, but none of the usual subjects (type inference, implicit search, inlining) showed up. Instead it seemed to do lots of complicated memberDenot/findMember/asSeenFrom operations in deep recursions with complicated types like

ZPartialServerEndpoint[R, A, B, I, E, O, -C] # EndpointType[A, I, E, T, R] ... # EndpointType[A, I, E, T, R]    (6 times)

turns out those complicated types can be avoided by more aggressive dealiasing. So I am trying that as a fix.

Projections P # X are types that we would like to avoid. If X is a class type, there's nothing we can do. If X is an abstract type, we use skolemization and rewrite to (x?: P).X. If X is an alias type we should simply dealias but this was not done before. This caused an exonential blowup in scala#19892, where we costructed types of the form ZPartialServerEndpoint[R, A, B, I, E, O, -C] # EndpointType[A, I, E, T, R] ... # EndpointType[A, I, E, T, R] When the were 5 or more such selections, sompile times blew up (33s for 5, timeout after 5 minutes for 6). I am still not qute sure where the blowup happened. Looking at stacktraces of random interrups it seemed to be in a deep recursion of memberDenot and asSeenFrom calls.I believe it would still be interesting to find out more about this, in case there are other similar situations where combinations of deep projections with wide applications cannot be avoided. But for this precise problem, eagerly dealising fixes it.

Projections P # X are types that we would like to avoid. If X is a class type, there's nothing we can do. If X is an abstract type, we use skolemization and rewrite to (x?: P).X. If X is an alias type we should simply dealias but this was not done before. This caused an exponential blowup in #19892, where we constructed types of the form ZPartialServerEndpoint[R, A, B, I, E, O, -C] # EndpointType[A, I, E, T, R] ... # EndpointType[A, I, E, T, R] When the were 5 or more such selections, compile times blew up (33s for 5, timeout after 5 minutes for 6). I am still not quite sure where the blowup happened. Looking at stacktraces of random interrupts it seemed to be in a deep recursion of memberDenot and asSeenFrom calls.I believe it would still be interesting to find out more about this, in case there are other similar situations where combinations of deep projections with wide applications cannot be avoided. But for this precise problem, eagerly dealiasing fixes it. Fixes #19892

Projections P # X are types that we would like to avoid. If X is a class type, there's nothing we can do. If X is an abstract type, we use skolemization and rewrite to (x?: P).X. If X is an alias type we should simply dealias but this was not done before. This caused an exonential blowup in #19892, where we costructed types of the form ZPartialServerEndpoint[R, A, B, I, E, O, -C] # EndpointType[A, I, E, T, R] ... # EndpointType[A, I, E, T, R] When the were 5 or more such selections, sompile times blew up (33s for 5, timeout after 5 minutes for 6). I am still not qute sure where the blowup happened. Looking at stacktraces of random interrups it seemed to be in a deep recursion of memberDenot and asSeenFrom calls.I believe it would still be interesting to find out more about this, in case there are other similar situations where combinations of deep projections with wide applications cannot be avoided. But for this precise problem, eagerly dealising fixes it. [Cherry-picked cd04d00][modified]

urieli added the stat:needs triage Every issue needs to have an "area" and "itype" label label Mar 6, 2024

WojciechMazur added itype:bug area:typer itype:performance and removed stat:needs triage Every issue needs to have an "area" and "itype" label labels Mar 11, 2024

WojciechMazur assigned odersky and noti0na1 Mar 11, 2024

WojciechMazur mentioned this issue Mar 12, 2024

Compilation performance regression on 3.4.0 #19924

Closed

odersky mentioned this issue Mar 12, 2024

Reduce projections of type aliases with class type prefixes #19931

Merged

odersky closed this as completed in #19931 Mar 27, 2024

Kordyjan added this to the 3.5.0 milestone May 10, 2024

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Project compiles in 18 seconds on scala 2, compilation never ends on scala 3 #19892

Project compiles in 18 seconds on scala 2, compilation never ends on scala 3 #19892

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odersky commented Mar 12, 2024

Project compiles in 18 seconds on scala 2, compilation never ends on scala 3 #19892

Project compiles in 18 seconds on scala 2, compilation never ends on scala 3 #19892

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urieli commented Mar 6, 2024

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