I'm trying to figure out how to set a flag in the Bazel BUILD file or .bazelrc file so that I can turn on the --warn_duplicate_resources or --no_duplicates flags when building a Java jar (actually Scala in my case, but the answer should be the same). I want to make it so that if Bazel sees duplicate files when packaging a jar (such as two different logback.xml files) the build will fail instead of picking one file and discarding the other.
I had some issues with shadowing of different resources when building a new jar using an old jar. After rummaging through the internet I found the --warn_duplicate_resources flag in the bazel code base in a few different places as well as a --no_duplicates flag. These seem like they would be helpful making sure to avoid the problem of multiple jar files defining the same resource file.
https://github.com/bazelbuild/bazel/blob/master/src/tools/singlejar/output_jar.cc
However, I have no idea what flags to put in the BUILD or .bazelrc files to get the --warn_duplicate_resources or --no_duplicates flags turned on. The java_library rule doesn't seem to have any direct connection and simply adding "build --warn_duplicate_resources" to the .bazelrc caused the build to fail.
https://docs.bazel.build/versions/master/be/java.html#java_library
Any help will be much appreciated, thanks!