Seeing errors like this?

Apr  5 12:32:04 socrates ?<11>email2trac : Failure sending notification on creation of ticket #1101: Can't extract file(s) to egg cache  The following error occurred while trying to extract file(s) to the Python egg cache:    [Errno 13] Permission denied: '/nonexistent'  The Python egg cache directory is currently set to:    /nonexistent/.python-eggs  Perhaps your account does not have write access to this directory?  You can change the cache directory by setting the PYTHON_EGG_CACHE environment variable to point to an accessible directory.<

The error message gives the solution:

mkdir  /tmp/trac/
chown www:www /tmp/trac/

Add the env statement to the virtualhost configuration:

SetEnv PYTHON_EGG_CACHE "/tmp/trac/"<br />

restart apache, problem solved.