buildifier-lint is printing all warnings twice

I noticed while fixing some warning, that all warnings are printed twice. Not sure where this is coming from since https://github.com/Warchant/pre-commit-buildifier/blob/bc3d86e27ae44c4b5e0380f82845aebbbea68e5f/src/pre_commit_buildifier.py#L126 is only a single call. I'll try to reproduce this in this repo with a test.