Bumpversion with setup.py case doesn't work because it needs a file to work on.

Hello,

I've tried the py-release stage, and it seems that it doesn't work by using setup.py only. The line here bumpversion ${TRACE+--verbose} --current-version "$py_cur_version" --commit --message "$py_commit_message" --tag --tag-name "{new_version}" "$py_release_part"

When there is no bumpconfig file, bumpversion will do nothing (setup.py will not be modified). Thus, the --commit option will try to commit nothing, which will fail.

Solution:

-> Add setup.py file as default args to bumpversion. or -> Remove this case and force user to define the bumpconfig file.

Do you want me to make a MR ?