A buildbot is up and running:
  http://buildbot.python.org/all/#/builders?tags=%2Bubsan

in order to see the errors though, you have to manually string search for "runtime error" in the giant test logs stdout.

At the moment, Modules/_ctypes/_ctypes.c dominates the error lists with misaligned access problems - I suggest filtering that out and looking for the others to start with for anyone working on these issues.