Please add "igwn_auth_utils/_version.py" to debian/clean
I'm not sure why this didn't show up previously (e.g. in https://git.ligo.org/computing/sccb/-/issues/876) - trying to re-package from Debian Bullseye to Ubuntu Focal (20.04), I came across this one: the file apparently gets touched/rewritten by debian/rules clean and afterwards conflicts with the tarball content.
Creating debian/clean with the content
igwn_auth_utils/_version.pyfixes the issue. Regressions affecting the binary package are not expected.
@duncanmmacleod: Please consider for the next release.