Regression in `softwaremill/tapir` - StaleSymbolException when compiling macros

[WojciechMazur]

OpenCB build logs

Compiler version

3.nightly, available in current main, but not in 3.6.0-RC1-bin-20240807-54344a1-NIGHTLY (last available, last night build failed)

Caused by 8a41389 introduced in #21339, reverted during backport to 3.5.0

Unhandled exception is thrown during inlining or when using -Yforce-sbt-phases in sbt-api

Minimized code

// schema.scala
//> using options -source:3.5

case class Schema[T](format: String):
  def asOption: Schema[Option[T]] = ???
  def name(name: Option[SName]): Schema[T] = ???
  def format(f: String): Schema[T] = ???

object Schema extends SchemaCompanionMacros:
  implicit def schemaForOption[T: Schema]: Schema[Option[T]] = 
    implicitly[Schema[T]]
    ???

trait SchemaCompanionMacros extends SchemaDerivation:
  given derivedStringBasedUnionEnumeration[S](using IsUnionOf[String, S]): Schema[S] = 
    val x: Schema[S] = ???
    x.name(None)

@main def Test =  
  case class Foo(x: Int) derives Schema

// schemaDerivation.scala
import scala.deriving.*
import scala.quoted.*

trait SName
abstract class CaseClass[Typeclass[_], Type]:
  def param: CaseClass.Param[Typeclass, Type]

object CaseClass:
  trait Param[Typeclass[_], Type]:
    type PType
    def typeclass: Typeclass[PType]
    

sealed trait IsUnionOf[T, A]
object IsUnionOf:
  transparent inline given derived[T, A]: IsUnionOf[T, A] = ${ deriveImpl[T, A] }
  private def deriveImpl[T, A](using quotes: Quotes): Expr[IsUnionOf[T, A]] = ???

trait SchemaDerivation:
  inline implicit def derived[T](implicit m: Mirror.Of[T]): Schema[T] = 
    val ctx: CaseClass[Schema, T] = ???
    val valueSchema = ctx.param.typeclass
    val format = valueSchema.format
    ???

Output (click arrow to expand)

  unhandled exception while running inlining on /Users/wmazur/projects/sandbox/src/main/scala/schema.scala

  An unhandled exception was thrown in the compiler.
  Please file a crash report here:
  https://github.com/scala/scala3/issues/new/choose
  For non-enriched exceptions, compile with -Xno-enrich-error-messages.

     while compiling: /Users/wmazur/projects/sandbox/src/main/scala/schema.scala
        during phase: inlining
                mode: Mode(ImplicitsEnabled)
     library version: version 2.13.14
    compiler version: version 3.5.0-RC6-bin-73c6e88-SNAPSHOT-git-73c6e88
            settings: -classpath /Users/wmazur/Library/Caches/Coursier/v1/https/scala3.westeurope.cloudapp.azure.com/maven2/3.5.0-RC6-bin-73c6e88-SNAPSHOT/org/scala-lang/scala3-library_3/3.5.0-RC6-bin-73c6e88-SNAPSHOT/scala3-library_3-3.5.0-RC6-bin-73c6e88-SNAPSHOT.jar:/Users/wmazur/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/org/scala-lang/scala-library/2.13.14/scala-library-2.13.14.jar -d /Users/wmazur/projects/sandbox/src/.scala-build/src_851f5ccd4f/classes/main -java-output-version 17 -sourceroot /Users/wmazur/projects/sandbox/src


  Exception while compiling /Users/wmazur/projects/sandbox/src/main/scala/schema.scala, /Users/wmazur/projects/sandbox/src/main/scala/schemaDerivation.scala

  An unhandled exception was thrown in the compiler.
  Please file a crash report here:
  https://github.com/scala/scala3/issues/new/choose
  For non-enriched exceptions, compile with -Xno-enrich-error-messages.

     while compiling: <no file>
        during phase: parser
                mode: Mode()
     library version: version 2.13.14
    compiler version: version 3.5.0-RC6-bin-73c6e88-SNAPSHOT-git-73c6e88
            settings: -classpath /Users/wmazur/Library/Caches/Coursier/v1/https/scala3.westeurope.cloudapp.azure.com/maven2/3.5.0-RC6-bin-73c6e88-SNAPSHOT/org/scala-lang/scala3-library_3/3.5.0-RC6-bin-73c6e88-SNAPSHOT/scala3-library_3-3.5.0-RC6-bin-73c6e88-SNAPSHOT.jar:/Users/wmazur/Library/Caches/Coursier/v1/https/repo1.maven.org/maven2/org/scala-lang/scala-library/2.13.14/scala-library-2.13.14.jar -d /Users/wmazur/projects/sandbox/src/.scala-build/src_851f5ccd4f/classes/main -java-output-version 17 -sourceroot /Users/wmazur/projects/sandbox/src

Exception in thread "main" dotty.tools.dotc.core.Denotations$StaleSymbolException: stale symbol; val format#4134 in class Schema, defined in Period(2.1-53), is referred to in run Period(3.12)
        at dotty.tools.dotc.core.Denotations$SingleDenotation.staleSymbolError(Denotations.scala:961)
        at dotty.tools.dotc.core.Denotations$SingleDenotation.bringForward(Denotations.scala:759)
        at dotty.tools.dotc.core.Denotations$SingleDenotation.toNewRun$1(Denotations.scala:806)
        at dotty.tools.dotc.core.Denotations$SingleDenotation.current(Denotations.scala:877)
        at dotty.tools.dotc.core.Symbols$Symbol.recomputeDenot(Symbols.scala:124)
        at dotty.tools.dotc.core.Symbols$Symbol.computeDenot(Symbols.scala:118)
        at dotty.tools.dotc.core.Symbols$Symbol.denot(Symbols.scala:109)
        at dotty.tools.dotc.core.Symbols$.toDenot(Symbols.scala:544)
        at dotty.tools.dotc.core.SourceLanguage$.apply(TypeErasure.scala:27)
        at dotty.tools.dotc.core.Denotations$SingleDenotation.signature(Denotations.scala:613)
        at dotty.tools.dotc.core.Types$NamedType.sigFromDenot(Types.scala:2435)
        at dotty.tools.dotc.core.Types$NamedType.currentSignature(Types.scala:2426)
        at dotty.tools.dotc.core.Types$NamedType.disambiguate(Types.scala:2552)
        at dotty.tools.dotc.core.Types$NamedType.memberDenot(Types.scala:2575)
        at dotty.tools.dotc.core.Types$NamedType.computeDenot(Types.scala:2543)
        at dotty.tools.dotc.core.Types$NamedType.denot(Types.scala:2502)
        at dotty.tools.dotc.core.Types$NamedType.computeSymbol(Types.scala:2449)
        at dotty.tools.dotc.core.Types$NamedType.symbol(Types.scala:2444)
        at dotty.tools.dotc.core.Types$Type.termSymbol(Types.scala:665)
        at dotty.tools.dotc.inlines.Inliner$$anon$4.apply(Inliner.scala:569)
        at dotty.tools.dotc.inlines.Inliner$$anon$4.apply(Inliner.scala:565)
        at dotty.tools.dotc.ast.TreeTypeMap.mapType(TreeTypeMap.scala:72)
        at dotty.tools.dotc.ast.TreeTypeMap.transform(TreeTypeMap.scala:105)
        at dotty.tools.dotc.ast.Trees$Instance$TreeMap.transform(Trees.scala:1597)
        at dotty.tools.dotc.ast.TreeTypeMap.transform(TreeTypeMap.scala:151)
        at dotty.tools.dotc.ast.Trees$Instance$TreeMap.transform$$anonfun$1(Trees.scala:1640)
        at scala.collection.immutable.List.mapConserve(List.scala:473)
        at dotty.tools.dotc.ast.Trees$Instance$TreeMap.transform(Trees.scala:1640)
        at dotty.tools.dotc.ast.Trees$Instance$TreeMap.transformSub(Trees.scala:1644)
        at dotty.tools.dotc.ast.TreeTypeMap.transformDefs(TreeTypeMap.scala:160)
        at dotty.tools.dotc.ast.TreeTypeMap.transform(TreeTypeMap.scala:120)
        at dotty.tools.dotc.ast.Trees$Instance$TreeMap.transform(Trees.scala:1542)
        at dotty.tools.dotc.ast.TreeTypeMap.transform(TreeTypeMap.scala:151)
        at dotty.tools.dotc.inlines.Inliner.inlined(Inliner.scala:623)
        at dotty.tools.dotc.inlines.Inlines$InlineCall.expand(Inlines.scala:491)
        at dotty.tools.dotc.inlines.Inlines$.inlineCall(Inlines.scala:163)
        at dotty.tools.dotc.transform.Inlining$InliningTreeMap.transform(Inlining.scala:100)
        at dotty.tools.dotc.ast.Trees$Instance$TreeMap.transform(Trees.scala:1597)
        at dotty.tools.dotc.ast.TreeMapWithImplicits.transform(TreeMapWithImplicits.scala:67)
        at dotty.tools.dotc.ast.TreeMapWithTrackedStats.transform(TreeMapWithTrackedStats.scala:63)
        at dotty.tools.dotc.transform.Inlining$InliningTreeMap.transformMemberDef(Inlining.scala:141)
        at dotty.tools.dotc.transform.Inlining$InliningTreeMap.transform(Inlining.scala:77)
        at dotty.tools.dotc.ast.tpd$TreeMapWithPreciseStatContexts.loop$2(tpd.scala:1240)
        at dotty.tools.dotc.ast.tpd$TreeMapWithPreciseStatContexts.transformStats(tpd.scala:1240)
        at dotty.tools.dotc.ast.tpd$TreeMapWithPreciseStatContexts.transformStats(tpd.scala:1242)
        at dotty.tools.dotc.ast.TreeMapWithImplicits.transform(TreeMapWithImplicits.scala:58)
        at dotty.tools.dotc.ast.TreeMapWithTrackedStats.transform(TreeMapWithTrackedStats.scala:63)
        at dotty.tools.dotc.transform.Inlining$InliningTreeMap.transform(Inlining.scala:101)
        at dotty.tools.dotc.ast.Trees$Instance$TreeMap.transform(Trees.scala:1602)
        at dotty.tools.dotc.ast.TreeMapWithImplicits.transform(TreeMapWithImplicits.scala:67)
        at dotty.tools.dotc.ast.TreeMapWithTrackedStats.transform(TreeMapWithTrackedStats.scala:60)
        at dotty.tools.dotc.transform.Inlining$InliningTreeMap.transformMemberDef(Inlining.scala:141)
        at dotty.tools.dotc.transform.Inlining$InliningTreeMap.transform(Inlining.scala:77)
        at dotty.tools.dotc.ast.tpd$TreeMapWithPreciseStatContexts.loop$2(tpd.scala:1240)
        at dotty.tools.dotc.ast.tpd$TreeMapWithPreciseStatContexts.transformStats(tpd.scala:1240)
        at dotty.tools.dotc.ast.tpd$TreeMapWithPreciseStatContexts.transformBlock(tpd.scala:1245)
        at dotty.tools.dotc.ast.Trees$Instance$TreeMap.transform(Trees.scala:1548)
        at dotty.tools.dotc.ast.TreeMapWithImplicits.transform(TreeMapWithImplicits.scala:43)
        at dotty.tools.dotc.ast.TreeMapWithTrackedStats.transform(TreeMapWithTrackedStats.scala:54)
        at dotty.tools.dotc.transform.Inlining$InliningTreeMap.transform(Inlining.scala:79)
        at dotty.tools.dotc.ast.TreeMapWithImplicits.transform(TreeMapWithImplicits.scala:50)
        at dotty.tools.dotc.ast.TreeMapWithTrackedStats.transform(TreeMapWithTrackedStats.scala:63)
        at dotty.tools.dotc.transform.Inlining$InliningTreeMap.transformMemberDef(Inlining.scala:141)
        at dotty.tools.dotc.transform.Inlining$InliningTreeMap.transform(Inlining.scala:77)
        at dotty.tools.dotc.ast.tpd$TreeMapWithPreciseStatContexts.loop$2(tpd.scala:1240)
        at dotty.tools.dotc.ast.tpd$TreeMapWithPreciseStatContexts.transformStats(tpd.scala:1240)
        at dotty.tools.dotc.ast.tpd$TreeMapWithPreciseStatContexts.transformStats(tpd.scala:1242)
        at dotty.tools.dotc.ast.TreeMapWithImplicits.transform(TreeMapWithImplicits.scala:58)
        at dotty.tools.dotc.ast.TreeMapWithTrackedStats.transform(TreeMapWithTrackedStats.scala:63)
        at dotty.tools.dotc.transform.Inlining$InliningTreeMap.transform(Inlining.scala:101)
        at dotty.tools.dotc.ast.Trees$Instance$TreeMap.transform(Trees.scala:1602)
        at dotty.tools.dotc.ast.TreeMapWithImplicits.transform(TreeMapWithImplicits.scala:67)
        at dotty.tools.dotc.ast.TreeMapWithTrackedStats.transform(TreeMapWithTrackedStats.scala:60)
        at dotty.tools.dotc.transform.Inlining$InliningTreeMap.transformMemberDef(Inlining.scala:141)
        at dotty.tools.dotc.transform.Inlining$InliningTreeMap.transform(Inlining.scala:77)
        at dotty.tools.dotc.ast.tpd$TreeMapWithPreciseStatContexts.loop$2(tpd.scala:1240)
        at dotty.tools.dotc.ast.tpd$TreeMapWithPreciseStatContexts.transformStats(tpd.scala:1240)
        at dotty.tools.dotc.ast.tpd$TreeMapWithPreciseStatContexts.transformStats(tpd.scala:1242)
        at dotty.tools.dotc.ast.Trees$Instance$TreeMap.transform(Trees.scala:1613)
        at dotty.tools.dotc.ast.TreeMapWithImplicits.transform(TreeMapWithImplicits.scala:67)
        at dotty.tools.dotc.ast.TreeMapWithTrackedStats.transform(TreeMapWithTrackedStats.scala:48)
        at dotty.tools.dotc.transform.Inlining$InliningTreeMap.transform(Inlining.scala:81)
        at dotty.tools.dotc.transform.Inlining$$anon$2.transform(Inlining.scala:63)
        at dotty.tools.dotc.transform.MacroTransform.run(MacroTransform.scala:20)
        at dotty.tools.dotc.transform.Inlining.run(Inlining.scala:39)
        at dotty.tools.dotc.core.Phases$Phase.runOn$$anonfun$1(Phases.scala:380)
        at scala.runtime.function.JProcedure1.apply(JProcedure1.java:15)
        at scala.runtime.function.JProcedure1.apply(JProcedure1.java:10)
        at scala.collection.immutable.List.foreach(List.scala:334)
        at dotty.tools.dotc.core.Phases$Phase.runOn(Phases.scala:373)
        at dotty.tools.dotc.transform.Inlining.runOn(Inlining.scala:43)
        at dotty.tools.dotc.Run.runPhases$1$$anonfun$1(Run.scala:343)
        at scala.runtime.function.JProcedure1.apply(JProcedure1.java:15)
        at scala.runtime.function.JProcedure1.apply(JProcedure1.java:10)
        at scala.collection.ArrayOps$.foreach$extension(ArrayOps.scala:1323)
        at dotty.tools.dotc.Run.runPhases$1(Run.scala:336)
        at dotty.tools.dotc.Run.compileUnits$$anonfun$1(Run.scala:384)
        at dotty.tools.dotc.Run.compileUnits$$anonfun$adapted$1(Run.scala:396)
        at dotty.tools.dotc.util.Stats$.maybeMonitored(Stats.scala:69)
        at dotty.tools.dotc.Run.compileUnits(Run.scala:396)
        at dotty.tools.dotc.Run.compileUnits(Run.scala:288)
        at dotty.tools.dotc.Run.compileSuspendedUnits(Run.scala:410)
        at dotty.tools.dotc.Driver.finish(Driver.scala:63)
        at dotty.tools.dotc.Driver.doCompile(Driver.scala:38)
        at dotty.tools.dotc.Driver.process(Driver.scala:201)
        at dotty.tools.dotc.Driver.process(Driver.scala:169)
        at dotty.tools.dotc.Driver.process(Driver.scala:181)
        at dotty.tools.dotc.Driver.main(Driver.scala:211)
        at dotty.tools.dotc.Main.main(Main.scala)
Compilation failed