This problem can be encountered when:
* upgrading gradle to some other version (for example: 2.3 -> 2.4), or by using a locally installed gradle and a wrapper which has some other version for example: * local default: 2.4 gradlew: 2.1
this can became annoying, when it happens usually it’s unexpected.
so i’ve taken the time to reproduce the issue
i’ve written some kind of test for this problem using bash
its output is failed, which means a class A24 have been kept - however it’s source have been already removed from the sourcetree.
this freaking forum doesn’t let me attach my shell script.
anyway: @see my SO post: http://stackoverflow.com/questions/31611043/gradle-classes-output-dir-contains-invalid-class-files-anomaly-after-switching