Lots of microdesc_free() warnings.
A user reported that while using the Tor Browser Bundle 2.4.17 on Mac OS 10.8, their log was filled up with more than a hundred messages saying the following:
[Warning] microdesc_free_(): Bug: microdesc_free() called from src/or/microdesc.c:379, but md was still referenced 1 node(s); held_by_nodes == 1