Gentoo: Troubles with Trac and mod_python-3.3.1?

If Trac doesn’t run anymore after an ’emerge -uD world’ (i.e. there’s a “500 Internal Server Error”) and Apache complains about “ImportError: No module named trac.web.modpython_frontend”, here’s the solution:

Gentoo Bug 230211 – www-apache/mod_python-3.3.1 – connobject.c:142: error: request for member ‘next’ in something not a structure or union

(IOW: Emerge mod_python-3.3.1-r1 from your local portage overlay and restart Apache)