Troubleshooting

Mysterious Crash in APT

For the following exception

[cookcc] An exception has occurred in apt (1.6.0_22). Please file a bug at the Java Developer Connection (http://java.sun.com/webapps/bugreport)  after checking the Bug Parade for duplicates. Include your program and the following diagnostic in your report.  Thank you.
[cookcc] java.lang.ClassCastException: com.sun.tools.javac.tree.JCTree$JCErroneous cannot be cast to com.sun.tools.javac.tree.JCTree$JCAnnotation
[cookcc]     at com.sun.tools.javac.comp.Annotate.enterAttributeValue(Annotate.java:205)
[cookcc]     at com.sun.tools.javac.comp.Annotate.enterAttributeValue(Annotate.java:219)
[cookcc]     at com.sun.tools.javac.comp.Annotate.enterAnnotation(Annotate.java:167)
[cookcc]     at com.sun.tools.javac.comp.MemberEnter.enterAnnotations(MemberEnter.java:743)
[cookcc]     at com.sun.tools.javac.comp.MemberEnter.access$300(MemberEnter.java:42)
[cookcc]     at com.sun.tools.javac.comp.MemberEnter$5.enterAnnotation(MemberEnter.java:711)
[cookcc]     at com.sun.tools.javac.comp.Annotate.flush(Annotate.java:95)
[cookcc]     at com.sun.tools.javac.comp.Annotate.enterDone(Annotate.java:87)
[cookcc]     at com.sun.tools.javac.comp.Enter.complete(Enter.java:485)
[cookcc]     at com.sun.tools.javac.comp.Enter.main(Enter.java:442)
[cookcc]     at com.sun.tools.apt.main.JavaCompiler.compile(JavaCompiler.java:250)
[cookcc]     at com.sun.tools.apt.main.Main.compile(Main.java:1102)
[cookcc]     at com.sun.tools.apt.main.Main.compile(Main.java:964)
[cookcc]     at com.sun.tools.apt.Main.processing(Main.java:95)
[cookcc]     at com.sun.tools.apt.Main.process(Main.java:43)
[cookcc]     at com.sun.tools.apt.Main.main(Main.java:34)

The cause of the issue is likely due to an extra comma after the last element in the annotation array.

@Shortcuts ( shortcuts = {
    @Shortcut (name="arg", pattern="[^=;, \\t\\r\\n\\f'\"]"),
    @Shortcut (name="ws", pattern="[ \\t\\r\\n\\f]"),
})

Eclipse Java Compiler (ECJ) does not report the extra comma in annotation arrays as a syntax error. Sun’s APT does not report the correct error message. So it gets a bit confusing. Once removing this extra comma, the problem would go away.

If the problem still persists, check your class path passed to APT. The incorrect PATH separator can lead to the similar back trace as well.