New Identity still occasionally crashes
In #6386 (closed), we backported a Mozilla fix for crashes during cache clearing at shutdown in an attempt to fix New Identity crash/deadlock. It may have fixed some instances, but more still remain. I have experienced both hangs and crashes in builds since that patch was updated.
I also added some loglines to New Identity in the last TBB release, so we hopefully have a better shot of at least narrowing this down now.
If anyone hits this a lot, go into about:config and set extensions.torbutton.loglevel to 3 and extensions.torbutton.logmethod to 0 and then run ./start-tor-browser --debug.
If you get a hang, we might be able to track it down based on the last logline that gets written to the debug file created in your Tor Browser directory that way. Unless buffering somewhere ruins our day :/.
Note that this will also log URLs to that file, though.