version 3.12 introduced a small python < 3 issue by using an fstring

[tim-nixon]

in the newest version line 2638 in init.py for bitbucket
url = f"{self._url_repo(project_key, repository_slug)}/archive"
uses an fstring which are not supported in python <3

I used
url = self._url_repo(project_key, repository_slug)+"/archive"
instead