Code review comment for lp:~wallyworld/launchpad/rename-private-team-795771

+ if not has_mailing_list:
+ reason = 'has a PPA'
+ elif not has_ppa:
+ reason = 'has a mailing list'

This made me blink.

Perhaps:
reasons = []
if has_mailing_list:
    reasons.append('has a mailing list')
if has_ppa:
    reasons.append('has a PPA')
assert reasons, 'rejecting but no reasons found!'
reason = ' and '.join(reasons)