This plugin appears to be incompatible with the TracAnnouncer plugin. I get this in the trac.log file:
Traceback (most recent call last):
File /usr/local/lib/python2.6/dist-packages/TracAnnouncer-0.12.1.dev-py2.6.egg/announcer/api.py, line 539, in _real_send
File /usr/local/lib/python2.6/dist-packages/TracAnnouncer-0.12.1.dev-py2.6.egg/announcer/filters.py, line 67, in filter_subscriptions
if permsys.check_permission(action, sid):
File /usr/local/lib/python2.6/dist-packages/Trac-0.12.1-py2.6.egg/trac/perm.py, line 454, in check_permission
File /usr/local/lib/python2.6/dist-packages/TracPrivateTickets-2.0.2-py2.6.egg/privatetickets/policy.py, line 34, in check_permission
TRAC_ADMIN in perm:
TypeError: argument of type NoneType is not iterable
The problem seems to stem from TracAnnouncer not sending a value for perm which the Trac permission system seems to allow and defaults its value to None.
My local fix was to change line 34 in privatetickets/policy.py to:
(perm and 'TRAC_ADMIN' in perm)
Once patched, the plugin appears to work well on Trac 0.12.