java.lang.IllegalArgumentException: already added: Lorg/hamcrest/BaseDescription; Conversion to Dalvik format failed with error 1

Question

First of all, there are at least 2 postings with the same problem but these solutions don\'t work anymore, at least not in my installation.

I\'m using m2e with Eclip

Answer 1

I found the solution. It depends on the JUnit version, because JUnit 4.10 adds JUnit library and hamcrest jar library, although JUnit 4.10 already contains all the hamcrest classes, so hamcrest exists twice then. If I switch back to JUnit 4.8.1, it doesn't add hamcrest as library and the error is gone.

This solution is actually a workaround. Usually the Eclipse Maven plugin should handle this, but Hamcrest/JUnit is a special problem, because JUnit includes Hamcrest, not as dependency, but in code.