Comment 13 for bug 924874

Apparently, the content of /var/lib/locales/supported.d/local never gets cleaned up and it retained the list of all locales ever generated. That at least explains why "locale-gen --purge" re-generated the same unwanted locales.

$ dpkg -S /var/lib/locales/supported.d/local
dpkg-query: no path found matching pattern /var/lib/locales/supported.d/local

So, I deleted it to see whether it would improve anything, before I ran "locale-gen --purge" again. This indeed finally solved the issue of generating spurrious locales. Now, remains the question of which package should perform this clean-up upon upgrade, so figure out where to commit the fix.

The question as to what appended unwanted locales to my .profile and to /etc/environment upon upgrading from Lucid to Precise remains open, though.