Hardened Tor Browser does not produce stack traces.
In legacy/trac#19515 (moved) and other bugs, we seem not to be getting full stack traces for issues.
It is common just to get: "==537696==AddressSanitizer: while reporting a bug found another one. Ignoring." or similar, rather than something that could be converted with the symbolizer as per https://trac.torproject.org/projects/tor/wiki/doc/TorBrowser/Hacking#ConvertASansstacktracemessage.
As per https://github.com/google/sanitizers/issues/391, it sounds like we may just need to add fast_unwind_on_fatal=1 to our ASAN_OPTIONS? Or maybe we need to update/switch to the latest stack unwinder: https://code.google.com/p/chromium/issues/detail?id=490275
I think it is pretty important to get this working, as I've experienced a couple crashes I couldn't do anything about. The ability to get valid crash report data from the wild from our hardened builds is extremely valuable.