ZipException when running Mwe2Launcher in IntelliJ IDEA (caused by broken classpath)

[jselbach]

When executing the Mwe2Launcher in an xText project using Maven and IntelliJ IDEA, the execution fails with a ZipException. As far as I can tell (using the debugger), this is caused by a non-JAR file (plexus-classworlds.license) being on the classpath. I have already opened an issue in the IntelliJ bugtracker for this but I think this also should be adressed in Mwe2/xText: a broken classpath entry should not (in my opinion) cause the execution to fail, a warning would suffice (including the broken file).

1    [org.eclipse.emf.mwe2.launch.runtime.Mwe2Launcher.main()] ERROR mf.mwe2.launch.runtime.Mwe2Launcher  - java.util.zip.ZipException: zip END header not found
org.eclipse.emf.common.util.WrappedException: java.util.zip.ZipException: zip END header not found
	at org.eclipse.xtext.mwe.PathTraverser.traverseArchive(PathTraverser.java:73)
	at org.eclipse.xtext.mwe.PathTraverser.findAllResourceUris(PathTraverser.java:50)
	at org.eclipse.xtext.mwe.PathTraverser.resolvePathes(PathTraverser.java:36)
	at org.eclipse.xtext.mwe.RuntimeResourceSetInitializer.getPathToUriMap(RuntimeResourceSetInitializer.java:55)
	at org.eclipse.xtext.mwe.RuntimeResourceSetInitializer.getInitializedResourceSet(RuntimeResourceSetInitializer.java:74)
	at org.eclipse.emf.mwe2.launch.runtime.Mwe2Runner.getConfiguredResourceSet(Mwe2Runner.java:132)
	at org.eclipse.emf.mwe2.launch.runtime.Mwe2Runner.run(Mwe2Runner.java:57)
	at org.eclipse.emf.mwe2.launch.runtime.Mwe2Runner.run(Mwe2Runner.java:53)
	at org.eclipse.emf.mwe2.launch.runtime.Mwe2Launcher.run(Mwe2Launcher.java:79)
	at org.eclipse.emf.mwe2.launch.runtime.Mwe2Launcher.main(Mwe2Launcher.java:37)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:566)
	at org.codehaus.mojo.exec.ExecJavaMojo$1.run(ExecJavaMojo.java:282)
	at java.base/java.lang.Thread.run(Thread.java:834)
Caused by: java.util.zip.ZipException: zip END header not found
	at java.base/java.util.zip.ZipFile$Source.zerror(ZipFile.java:1581)
	at java.base/java.util.zip.ZipFile$Source.findEND(ZipFile.java:1476)
	at java.base/java.util.zip.ZipFile$Source.initCEN(ZipFile.java:1483)
	at java.base/java.util.zip.ZipFile$Source.<init>(ZipFile.java:1288)
	at java.base/java.util.zip.ZipFile$Source.get(ZipFile.java:1251)
	at java.base/java.util.zip.ZipFile$CleanableResource.<init>(ZipFile.java:732)
	at java.base/java.util.zip.ZipFile$CleanableResource.get(ZipFile.java:849)
	at java.base/java.util.zip.ZipFile.<init>(ZipFile.java:247)
	at java.base/java.util.zip.ZipFile.<init>(ZipFile.java:177)
	at java.base/java.util.zip.ZipFile.<init>(ZipFile.java:191)
	at org.eclipse.xtext.mwe.PathTraverser.traverseArchive(PathTraverser.java:58)
	... 15 more

[cdietrich]

maybe there is something broken in your maven repo.
can you try with a dedicated maven repo from command line?
e.g. -Dmaven.repo.local=.m2 or debug the workflow and check which is the bad zip?

[jselbach]

The "bad ZIP" is the file plexus-classworlds.license which is part of the IntelliJ installation. This is a plain text file, not a ZIP.

[cdietrich]

thus the question would be: why is this file added to pathes.
is license a file extension of yours?

[jselbach]

The file is part of the IntelliJ IDEA installation, which is why I've initially opened the bug report there (link in my first post). Why the file is there and why it gets added to the classpath by IntelliJ is beyond me.

I have opened this issue to see if the problem could also be adressed in xText: I believe it is problematic that the Maven goal fails with a ZIP exception and no information which file causes the problem. This had stumped several colleages until I decided to debug the build process. So either more information (i.e. which file caused the exception to be thrown) or not failing the build at all and only issuing a warning would be great.

Also I'm sorry if this is the wrong bug tracker and it should be moved to one of the Mwe2 projects at eclipse.org. But the top stack trace entry says org.eclipse.xtext, so I figured this is the right place.

[cdietrich]

PathTraverser is part of the xtext-core codebase the issue location is correct.

[cdietrich]

logging added.

[SimonCockx]

I'm experiencing the same issue on Xtext 2.27.0. Although the logging helps with identifying the faulty file, it would be nice if PathTraverser would just ignore this file, instead of crashing.