http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59136
--- Comment #12 from Alexander Potapenko <glider at google dot com> --- I wonder if https://code.google.com/p/address-sanitizer/issues/detail?id=253 is relevant here. In the case TSan tests do fork() (which I'm not expecting from them, however) the parent and the child will share the same symbolizer, which will just fail to multiplex their queries.
