Description Javier Armendáriz 2018-10-29 08:09:38 EDT

This error appears in a project that uses log4j 2 as a dependency and has classes with annotations when compiling using the batch compiler. However, compiling from the IDE returns no error/warnings.

This is the stacktrace ecj returned:

Processing annotations
java.lang.IllegalArgumentException: Unknown location : CLASS_OUTPUT
    at org.eclipse.jdt.internal.compiler.apt.util.EclipseFileManager.getFileForOutput(EclipseFileManager.java:436)
    at org.eclipse.jdt.internal.compiler.apt.dispatch.BatchFilerImpl.createResource(BatchFilerImpl.java:89)
    at org.apache.logging.log4j.core.config.plugins.processor.PluginProcessor.writeCacheFile(PluginProcessor.java:117)
    at org.apache.logging.log4j.core.config.plugins.processor.PluginProcessor.process(PluginProcessor.java:78)
    at org.eclipse.jdt.internal.compiler.apt.dispatch.RoundDispatcher.handleProcessor(RoundDispatcher.java:142)
    at org.eclipse.jdt.internal.compiler.apt.dispatch.RoundDispatcher.round(RoundDispatcher.java:124)
    at org.eclipse.jdt.internal.compiler.apt.dispatch.BaseAnnotationProcessorManager.processAnnotations(BaseAnnotationProcessorManager.java:162)
    at org.eclipse.jdt.internal.compiler.Compiler.processAnnotations(Compiler.java:940)
    at org.eclipse.jdt.internal.compiler.Compiler.compile(Compiler.java:450)
    at org.eclipse.jdt.internal.compiler.Compiler.compile(Compiler.java:426)
    at org.eclipse.jdt.internal.compiler.batch.Main.performCompilation(Main.java:4693)
    at org.eclipse.jdt.internal.compiler.batch.Main.compile(Main.java:1781)
    at org.eclipse.jdt.internal.compiler.batch.Main.main(Main.java:1485)
Processing annotations
No elements to process
1. ERROR: Unknown location : CLASS_OUTPUT
1 problem (1 error)


I attached to this issue a minimal test scenario. This was tested using ecj 4.7 and 4.9, with Oracle's and OpenJDK Java8 and in Ubuntu 18.04 and MacOSX High Sierra, and the error can be reproduced in all scenarios.