trac is currently a bit of a trouble case. Most python packages aren't available for python 2 anymore and trac is not yet python3. Next trac version will be python3 and the issues hopefully solved (spambayes for the spamfilter is also a trouble case as this is not yet python3, but that probably can be fixed). So ATM my recommendation is to not try trac on Tumbleweed, but rather on LEap 15.2.