NPE in Symbol.isValidInCurrentRun

[sir-wabbit]

minimized code

class A[F[_], X <: F[Int]](x: X) extends AnyVal

Stack trace

java.lang.NullPointerException while compiling testing/Test.scala
Exception in thread "main" java.lang.NullPointerException
	at dotty.tools.dotc.core.Symbols$Symbol.isValidInCurrentRun(Symbols.scala:511)
	at dotty.tools.dotc.core.Types$NamedType.computeSymbol(Types.scala:1871)
	at dotty.tools.dotc.core.Types$NamedType.symbol(Types.scala:1866)
	at dotty.tools.dotc.core.TypeApplications$.typeParams$extension(TypeApplications.scala:173)
	at dotty.tools.dotc.core.TypeApplications$.appliedTo$extension(TypeApplications.scala:359)
	at dotty.tools.dotc.core.Types$AppliedType.derivedAppliedType(Types.scala:3635)
	at dotty.tools.dotc.core.Types$TypeMap.derivedAppliedType(Types.scala:4511)
	at dotty.tools.dotc.core.Types$TypeMap.mapOver(Types.scala:4569)
	at dotty.tools.dotc.core.Substituters.substParams(Substituters.scala:157)
	at dotty.tools.dotc.core.Contexts$Context.substParams(Contexts.scala:75)
	at dotty.tools.dotc.core.Substituters$SubstParamsMap.apply(Substituters.scala:193)
	at dotty.tools.dotc.core.Types$TypeMap.mapOver(Types.scala:4581)
	at dotty.tools.dotc.core.Substituters.substParams(Substituters.scala:157)
	at dotty.tools.dotc.core.Contexts$Context.substParams(Contexts.scala:75)
	at dotty.tools.dotc.core.Types$Type.substParams(Types.scala:1525)
	at dotty.tools.dotc.core.Types$LambdaType.instantiateParamInfos$$anonfun$1(Types.scala:3044)
	at scala.collection.immutable.List.mapConserve(List.scala:444)
	at dotty.tools.dotc.core.Types$LambdaType.instantiateParamInfos(Types.scala:3044)
	at dotty.tools.dotc.core.Types$MethodOrPoly.instantiateParamInfos(Types.scala:3103)
	at dotty.tools.dotc.ast.tpd$.$anonfun$1(tpd.scala:226)
	at dotty.tools.dotc.core.Symbols.newTypeParams(Symbols.scala:290)
	at dotty.tools.dotc.core.Contexts$Context.newTypeParams(Contexts.scala:75)
	at dotty.tools.dotc.ast.tpd$.polyDefDef(tpd.scala:226)
	at dotty.tools.dotc.transform.FullParameterization.fullyParameterizedDef(FullParameterization.scala:217)
	at dotty.tools.dotc.transform.ExtensionMethods.fullyParameterizedDef(ExtensionMethods.scala:39)
	at dotty.tools.dotc.transform.ExtensionMethods.transformDefDef(ExtensionMethods.scala:172)
	at dotty.tools.dotc.transform.MegaPhase.goDefDef(MegaPhase.scala:941)
	at dotty.tools.dotc.transform.MegaPhase.goDefDef(MegaPhase.scala:942)
	at dotty.tools.dotc.transform.MegaPhase.transformNamed$1(MegaPhase.scala:248)
	at dotty.tools.dotc.transform.MegaPhase.transformTree(MegaPhase.scala:394)
	at dotty.tools.dotc.transform.MegaPhase.transformStat$2(MegaPhase.scala:404)
	at dotty.tools.dotc.transform.MegaPhase.$anonfun$1(MegaPhase.scala:409)
	at scala.collection.immutable.List.mapConserve(List.scala:444)
	at dotty.tools.dotc.transform.MegaPhase.transformStats(MegaPhase.scala:409)
	at dotty.tools.dotc.transform.MegaPhase.transformUnnamed$1(MegaPhase.scala:339)
	at dotty.tools.dotc.transform.MegaPhase.transformTree(MegaPhase.scala:396)
	at dotty.tools.dotc.transform.MegaPhase.transformNamed$1(MegaPhase.scala:251)
	at dotty.tools.dotc.transform.MegaPhase.transformTree(MegaPhase.scala:394)
	at dotty.tools.dotc.transform.MegaPhase.transformStat$2(MegaPhase.scala:404)
	at dotty.tools.dotc.transform.MegaPhase.$anonfun$1(MegaPhase.scala:409)
	at scala.collection.immutable.List.mapConserve(List.scala:444)
	at dotty.tools.dotc.transform.MegaPhase.transformStats(MegaPhase.scala:409)
	at dotty.tools.dotc.transform.MegaPhase.mapPackage$1(MegaPhase.scala:356)
	at dotty.tools.dotc.transform.MegaPhase.transformUnnamed$1(MegaPhase.scala:359)
	at dotty.tools.dotc.transform.MegaPhase.transformTree(MegaPhase.scala:396)
	at dotty.tools.dotc.transform.MegaPhase.transformUnit(MegaPhase.scala:415)
	at dotty.tools.dotc.transform.MegaPhase.run(MegaPhase.scala:427)
	at dotty.tools.dotc.core.Phases$Phase.runOn$$anonfun$1(Phases.scala:315)
	at scala.collection.immutable.List.map(List.scala:219)
	at dotty.tools.dotc.core.Phases$Phase.runOn(Phases.scala:316)
	at dotty.tools.dotc.Run.runPhases$4$$anonfun$4(Run.scala:161)
	at dotty.runtime.function.JProcedure1.apply(JProcedure1.java:15)
	at dotty.runtime.function.JProcedure1.apply(JProcedure1.java:10)
	at scala.collection.ArrayOps$.foreach$extension(ArrayOps.scala:1323)
	at dotty.tools.dotc.Run.runPhases$5(Run.scala:171)
	at dotty.tools.dotc.Run.compileUnits$$anonfun$1(Run.scala:179)
	at dotty.runtime.function.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.java:12)
	at dotty.tools.dotc.util.Stats$.maybeMonitored(Stats.scala:65)
	at dotty.tools.dotc.Run.compileUnits(Run.scala:186)
	at dotty.tools.dotc.Run.compileSources(Run.scala:123)
	at dotty.tools.dotc.Run.compile(Run.scala:106)
	at dotty.tools.dotc.Driver.doCompile(Driver.scala:36)
	at dotty.tools.dotc.Driver.process(Driver.scala:189)
	at dotty.tools.dotc.Driver.process(Driver.scala:158)
	at dotty.tools.dotc.Driver.process(Driver.scala:170)
	at dotty.tools.dotc.Driver.main(Driver.scala:197)
	at dotty.tools.dotc.Main.main(Main.scala)