Why do Git and Debian only use a mailing list and not an issue tracker?

The title is slightly misleading – neither does Debian primarily use ‘mailing lists’ to report/manage bugs, nor does it not have an issue tracker. debbugs is operated by email, yes, but it also has a (read-only) web interface and is pretty much by definition an issue tracker, uploads to the Debian archive, e.g., can be ‘tagged’ as closing particular bugs.

"bug tracker" is a function. "mailing list" is a mechanism.<p>A mailing list can be a bug tracker. So can a spreadsheet. So can an RDBMS-backed web app. So can index cards stuck to a wall.<p>Obviously, each of these mechanisms has strengths and weaknesses as a bug tracker.

Not mentioned: Mailing lists are idiot filters. If you can't use one, chances are rather low that you have anything of worth to say.<p>Just look at the issue trackers for many other open source projects: flooded with <i>"me too!"</i> comments.