It wasn't proprietary software, but I used to work with a sustaining engineer who ran Firefox in a gdb session. He was a "tab hoarder" and this was before the days it would save your session; when it reset he complained that he'd lose days of context. I watched him hand-repair a SIGSEGV from a null pointer dereference. As he was doing so he explained he'd reported this particular bug a few weeks ago but "Mozilla's triage was taking a while." A few keystrokes later he'd backed up a couple of frames, set a condition variable to avoid the bad code, and continued the process without interruption. Hugely impressive.
I’m surprised the performance overhead of running a whole web browser inside a debugger was remotely tolerable for daily use.
Wouldn’t it have been easier (and way more performant) to just whip up a quick extension that dumps the list of open tabs to disk every time a tab is opened/closed? I recall session savers being some of the very first extensions available for Firefox.
An engineer dedicated to bugfixes and crash investigations, rather than feature development. Not a common title anymore, but you'll still find them attached to products that use their own kernel, like switches and network storage.
