The following compilation is ill-formed: there is cyclic inheritance in T. When annotation processing is enabled javac fails to reject the compilation and instead crashes.

=== P.java
import java.util.Set;
import javax.annotation.processing.AbstractProcessor;
import javax.annotation.processing.RoundEnvironment;
import javax.annotation.processing.SupportedAnnotationTypes;
import javax.lang.model.SourceVersion;
import javax.lang.model.element.TypeElement;

@SupportedAnnotationTypes("*")
public class P extends AbstractProcessor {
  public SourceVersion getSupportedSourceVersion() {
    return SourceVersion.latestSupported();
  }

  public boolean process(Set<? extends TypeElement> annotations, RoundEnvironment roundEnv) {
    return false;
  }
}
=== T.java
package p;

import p.T.I;

abstract class T implements I {
  interface I {
    default boolean fieldTypeReplaced() {
      return false;
    }
  }
}
===

$ javac P.java
$ javac -processor P T.java
An exception has occurred in the compiler (9.0.1). Please file a bug against the Java compiler via the Java bug reporting page (http://bugreport.java.com) after checking the Bug Database (http://bugs.java.com) for duplicates. Include your program and the following diagnostic in your report. Thank you.
java.lang.NullPointerException
        at jdk.compiler/com.sun.tools.javac.comp.MemberEnter.visitMethodDef(MemberEnter.java:184)
        at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCMethodDecl.accept(JCTree.java:866)
        at jdk.compiler/com.sun.tools.javac.comp.MemberEnter.memberEnter(MemberEnter.java:161)
        at jdk.compiler/com.sun.tools.javac.comp.MemberEnter.memberEnter(MemberEnter.java:173)
        at jdk.compiler/com.sun.tools.javac.comp.TypeEnter$MembersPhase.finishClass(TypeEnter.java:947)
        at jdk.compiler/com.sun.tools.javac.comp.TypeEnter$MembersPhase.runPhase(TypeEnter.java:931)
        at jdk.compiler/com.sun.tools.javac.comp.TypeEnter$Phase.doCompleteEnvs(TypeEnter.java:270)
        at jdk.compiler/com.sun.tools.javac.comp.TypeEnter$MembersPhase.doCompleteEnvs(TypeEnter.java:866)
        at jdk.compiler/com.sun.tools.javac.comp.TypeEnter$Phase.completeEnvs(TypeEnter.java:245)
        at jdk.compiler/com.sun.tools.javac.comp.TypeEnter$Phase.completeEnvs(TypeEnter.java:254)
        at jdk.compiler/com.sun.tools.javac.comp.TypeEnter$Phase.completeEnvs(TypeEnter.java:254)
        at jdk.compiler/com.sun.tools.javac.comp.TypeEnter$Phase.completeEnvs(TypeEnter.java:254)
        at jdk.compiler/com.sun.tools.javac.comp.TypeEnter.complete(TypeEnter.java:195)
        at jdk.compiler/com.sun.tools.javac.code.Symbol.complete(Symbol.java:633)
        at jdk.compiler/com.sun.tools.javac.code.Symbol$ClassSymbol.complete(Symbol.java:1314)
        at jdk.compiler/com.sun.tools.javac.comp.Enter.complete(Enter.java:577)
        at jdk.compiler/com.sun.tools.javac.comp.Enter.main(Enter.java:554)
        at jdk.compiler/com.sun.tools.javac.main.JavaCompiler.enterTrees(JavaCompiler.java:1052)
        at jdk.compiler/com.sun.tools.javac.main.JavaCompiler.compile(JavaCompiler.java:923)
        at jdk.compiler/com.sun.tools.javac.main.Main.compile(Main.java:302)
        at jdk.compiler/com.sun.tools.javac.main.Main.compile(Main.java:162)
        at jdk.compiler/com.sun.tools.javac.Main.compile(Main.java:57)
        at jdk.compiler/com.sun.tools.javac.Main.main(Main.java:43)