In our specfile we have

Source13: .abignore

Here is the regular expression that parses this
https://pagure.io/rpkg/blob/master/f/pyrpkg/init.py#_4574

bud, the w+ does not match the dot at the start of the file, so no substitution is done and we end with 'Source13: .abignore' in the list instead of '.abignore'

And because of that I see Source file 'Source13: .abignore' was neither listed in the 'sources' file nor tracked in git nor listed in additional sources. Push operation was cancelled