In our crash handling system, the MallocFreeOStreamGuard checks for re-entrant signal handling e.g., thread X crashed, the signal handler started running, the signal handler crashed, and thus a signal was delivered while executing the signal handler. If this happens, instead of proceeding, it silently calls endProcessWithSignal(signum), which restores the default signal handler and then re-raises the signal. Typically, we'd expect this to silently dump core.

However, this can appear as a silent crash (for example, if the system has coredumps disabled) or a crash where we just go silent in the middle of logging the crash. For example, we might log the first few messages from the crash handler and then go silent before we log a stacktrace.

There's not much we can do if the crash handler crashes, but we might want to consider creating a bit more noise so we don't just silently die in the middle of handling a crash.