Nullness checker crash: StructuralEqualityComparer: unexpected combination

[Calvin-L]

Checker Framework 3.46.0 (latest release).

[ERROR] error: StructuralEqualityComparer: unexpected combination:  type: [TYPEVAR class org.checkerframework.framework.type.AnnotatedTypeMirror$AnnotatedTypeVariable] T extends Object  supertype: [DECLARED class org.checkerframework.framework.type.AnnotatedTypeMirror$AnnotatedDeclaredType] BiPredicate<REDACTED, String>
[ERROR] @Initialized @NonNull BiPredicate<@Initialized @NonNull REDACTED, @Initialized @NonNull String>
[ERROR]     visitHistory = org.checkerframework.framework.type.StructuralEqualityVisitHistory@46d9c0b4
[ERROR]   ; The Checker Framework crashed.  Please report the crash.  Version: Checker Framework 3.46.0. 
[ERROR]   Compilation unit: [REDACTED]
[ERROR]   Last visited tree at line 23 column 5:
[ERROR]       private final Supplier<BiPredicate<REDACTED, String>> supplier = Suppliers.memoize(() -> this:accept);
[ERROR]   Exception: java.lang.Throwable; java.lang.Throwable
[ERROR]     at org.checkerframework.javacutil.BugInCF.<init>(BugInCF.java:26)
[ERROR]     at org.checkerframework.framework.type.visitor.AtmComboVisitor.defaultAction(AtmComboVisitor.java:66)
[ERROR]     at org.checkerframework.framework.type.StructuralEqualityComparer.defaultAction(StructuralEqualityComparer.java:49)
[ERROR]     at org.checkerframework.framework.type.StructuralEqualityComparer.defaultAction(StructuralEqualityComparer.java:30)
[ERROR]     at org.checkerframework.framework.type.visitor.AbstractAtmComboVisitor.visitTypevar_Declared(AbstractAtmComboVisitor.java:512)
[ERROR]     at org.checkerframework.framework.util.AtmCombo.accept(AtmCombo.java:589)
[ERROR]     at org.checkerframework.framework.type.StructuralEqualityComparer.areEqual(StructuralEqualityComparer.java:84)
[ERROR]     at org.checkerframework.framework.type.StructuralEqualityComparer.areEqualInHierarchy(StructuralEqualityComparer.java:94)
[ERROR]     at org.checkerframework.framework.type.DefaultTypeHierarchy.areEqualInHierarchy(DefaultTypeHierarchy.java:339)
[ERROR]     at org.checkerframework.framework.type.DefaultTypeHierarchy.isContainedBy(DefaultTypeHierarchy.java:415)
[ERROR]     at org.checkerframework.framework.type.DefaultTypeHierarchy.isContainedMany(DefaultTypeHierarchy.java:645)
[ERROR]     at org.checkerframework.framework.type.DefaultTypeHierarchy.visitTypeArgs(DefaultTypeHierarchy.java:609)
[ERROR]     at org.checkerframework.framework.type.DefaultTypeHierarchy.visitDeclared_Declared(DefaultTypeHierarchy.java:542)
[ERROR]     at org.checkerframework.framework.type.DefaultTypeHierarchy.visitDeclared_Declared(DefaultTypeHierarchy.java:49)
[ERROR]     at org.checkerframework.framework.util.AtmCombo.accept(AtmCombo.java:313)
[ERROR]     at org.checkerframework.framework.type.DefaultTypeHierarchy.isSubtype(DefaultTypeHierarchy.java:259)
[ERROR]     at org.checkerframework.framework.type.DefaultTypeHierarchy.isSubtype(DefaultTypeHierarchy.java:137)
[ERROR]     at org.checkerframework.common.basetype.BaseTypeVisitor.commonAssignmentCheck(BaseTypeVisitor.java:3139)
[ERROR]     at org.checkerframework.checker.nullness.NullnessVisitor.commonAssignmentCheck(NullnessVisitor.java:250)
[ERROR]     at org.checkerframework.common.basetype.BaseTypeVisitor.commonAssignmentCheck(BaseTypeVisitor.java:3114)
[ERROR]     at org.checkerframework.checker.nullness.NullnessVisitor.commonAssignmentCheck(NullnessVisitor.java:231)
[ERROR]     at org.checkerframework.common.basetype.BaseTypeVisitor.commonAssignmentCheck(BaseTypeVisitor.java:3033)
[ERROR]     at org.checkerframework.checker.initialization.InitializationVisitor.commonAssignmentCheck(InitializationVisitor.java:136)
[ERROR]     at org.checkerframework.checker.nullness.NullnessVisitor.commonAssignmentCheck(NullnessVisitor.java:179)
[ERROR]     at org.checkerframework.common.basetype.BaseTypeVisitor.visitVariable(BaseTypeVisitor.java:1617)
[ERROR]     at org.checkerframework.checker.initialization.InitializationVisitor.visitVariable(InitializationVisitor.java:158)
[ERROR]     at org.checkerframework.checker.initialization.InitializationVisitor.visitVariable(InitializationVisitor.java:51)
[ERROR]     at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCVariableDecl.accept(JCTree.java:1045)
[ERROR]     at jdk.compiler/com.sun.source.util.TreePathScanner.scan(TreePathScanner.java:86)
[ERROR]     at org.checkerframework.framework.source.SourceVisitor.scan(SourceVisitor.java:92)
[ERROR]     at org.checkerframework.common.basetype.BaseTypeVisitor.scan(BaseTypeVisitor.java:408)
[ERROR]     at org.checkerframework.common.basetype.BaseTypeVisitor.scan(BaseTypeVisitor.java:189)
[ERROR]     at jdk.compiler/com.sun.source.util.TreeScanner.scanAndReduce(TreeScanner.java:96)
[ERROR]     at jdk.compiler/com.sun.source.util.TreeScanner.scan(TreeScanner.java:111)
[ERROR]     at jdk.compiler/com.sun.source.util.TreeScanner.scanAndReduce(TreeScanner.java:119)
[ERROR]     at jdk.compiler/com.sun.source.util.TreeScanner.visitClass(TreeScanner.java:203)
[ERROR]     at org.checkerframework.framework.source.SourceVisitor.visitClass(SourceVisitor.java:98)
[ERROR]     at org.checkerframework.common.basetype.BaseTypeVisitor.processClassTree(BaseTypeVisitor.java:612)
[ERROR]     at org.checkerframework.checker.initialization.InitializationVisitor.processClassTree(InitializationVisitor.java:246)
[ERROR]     at org.checkerframework.checker.nullness.NullnessVisitor.processClassTree(NullnessVisitor.java:601)
[ERROR]     at org.checkerframework.common.basetype.BaseTypeVisitor.visitClass(BaseTypeVisitor.java:558)
[ERROR]     at org.checkerframework.common.basetype.BaseTypeVisitor.visitClass(BaseTypeVisitor.java:189)
[ERROR]     at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCClassDecl.accept(JCTree.java:860)
[ERROR]     at jdk.compiler/com.sun.source.util.TreePathScanner.scan(TreePathScanner.java:60)
[ERROR]     at org.checkerframework.framework.source.SourceVisitor.visit(SourceVisitor.java:86)
[ERROR]     at org.checkerframework.framework.source.SourceChecker.typeProcess(SourceChecker.java:1094)
[ERROR]     at org.checkerframework.common.basetype.BaseTypeChecker.typeProcess(BaseTypeChecker.java:559)
[ERROR]     at org.checkerframework.javacutil.AbstractTypeProcessor$AttributionTaskListener.finished(AbstractTypeProcessor.java:188)
[ERROR]     at jdk.compiler/com.sun.tools.javac.api.ClientCodeWrapper$WrappedTaskListener.finished(ClientCodeWrapper.java:854)
[ERROR]     at jdk.compiler/com.sun.tools.javac.api.MultiTaskListener.finished(MultiTaskListener.java:132)
[ERROR]     at jdk.compiler/com.sun.tools.javac.main.JavaCompiler.flow(JavaCompiler.java:1397)
[ERROR]     at jdk.compiler/com.sun.tools.javac.main.JavaCompiler.flow(JavaCompiler.java:1354)
[ERROR]     at jdk.compiler/com.sun.tools.javac.main.JavaCompiler.desugar(JavaCompiler.java:1495)
[ERROR]     at jdk.compiler/com.sun.tools.javac.main.JavaCompiler.desugar(JavaCompiler.java:1411)
[ERROR]     at jdk.compiler/com.sun.tools.javac.main.JavaCompiler.compile(JavaCompiler.java:946)
[ERROR]     at jdk.compiler/com.sun.tools.javac.main.Main.compile(Main.java:317)
[ERROR]     at jdk.compiler/com.sun.tools.javac.main.Main.compile(Main.java:176)
[ERROR]     at jdk.compiler/com.sun.tools.javac.Main.compile(Main.java:64)
[ERROR]     at jdk.compiler/com.sun.tools.javac.Main.main(Main.java:50)

I was not able to make a minimized version that exhibits the bug. Here is roughly what the code looks like:

import java.util.function.BiPredicate;
import java.util.function.Supplier;

class Suppliers {
    public static <T> Supplier<T> memoize(Supplier<T> delegate) {
        return delegate;
    }
}

public abstract class Crash_3_46_0_BiPredicate {

    private final Supplier<BiPredicate<Integer, String>> supplier = Suppliers.memoize(() -> this::accept);

    protected abstract boolean accept(Integer scope, String name);

}

But this minimal example reports something different (and equally cryptic):

Compilation failure
error: AsSuperVisitor: type is not an erased subtype of supertype.

In both projects I can fix the crash by manually specifying the <T> parameter to Suppliers.memoize:

Suppliers.<BiPredicate<Integer, String>>memoize(() -> this::accept)

Fixing the crash reveals a true initialization error.

Possibly related to #6755 or #6671.