I get the following master branch:
Multiple artifacts of the module com.google.protobuf#protobuf-java;3.4.0 are retrieved to the same file! Update the retrieve pattern to fix this error
The retrieve pattern I am using is :
within my Ivy.xml file I'm not directly pulling in the dependency of protobuf, so its coming in as a transitive (probably twice or even 3 times)
I suspect 2 transitives are using the same library and the retrieve is upset because it will be overwriting it.
If 2 or more transitives have the same groupId, artifactId, and versionId, they effectively "are" the same file - so retrieve should not error out.