Truncated backtraces on OS X

[michaelwoerister]

The original report is here: https://bugzilla.mozilla.org/show_bug.cgi?id=1496503

Apparently backtraces (sometimes?) get truncated on OS X as seen here:

++DOMWINDOW == 3 (0x116c70800) [pid = 89605] [serial = 3] [outer = 0x10bd5a200]
thread '' panicked at 'assertion failed: texture.state() == TextureState::Uninitialized', gfx/webrender/src/device/gl.rs:1177:9
stack backtrace:
   0:        0x10edc78bf - std::sys::unix::backtrace::tracing::imp::unwind_backtrace::hdfdb4ba75a1dcb88
   1:        0x10eda034a - std::sys_common::backtrace::print::h5823bdde4d2f8639
   2:        0x10edd00c3 - std::panicking::default_hook::{{closure}}::h06fc925781e26cfe
   3:        0x10edcfe4c - std::panicking::default_hook::hdfdcc6f72e7aec0a
   4:        0x10edd07b7 - std::panicking::rust_panic_with_hook::h28749c6c929f49fc
Redirecting call to abort() to mozalloc_abort

Hit MOZ_CRASH() at /files/mozilla/mc/q/memory/mozalloc/mozalloc_abort.cpp:35
Crash Annotation GraphicsCriticalError: |[C0][GFX1-]: Receive IPC close with reason=AbnormalShutdown (t=1.3491) Hit MOZ_CRASH(Aborting on channel error.) at /files/mozilla/mc/q/ipc/glue/MessageChannel.cpp:2662
Hit MOZ_CRASH(MachExceptionHandler: Failed to forward to the previous handler!) at /files/mozilla/mc/q/js/src/ds/MemoryProtectionExceptionHandler.cpp:671

Is this a known issue?

cc @bholley

[alexcrichton]

I can't recall ever seeing this before, but it almost looks like we're calling abort while backtracing which may mean something else is awry? (or is "redirecting call to abort()" expected?)

[staktrace]

I see the same thing as what @bholley reported - when firefox runs into a panic it prints the 5 (mostly useless) frames. If I'm running in lldb I can use the bt command to get a full stack. My mozconfig is at https://github.com/staktrace/moz-scripts/blob/4a18644e77acf03d145fa01e2f68191e0b32b9a0/mozconfig.Darwin-host-debug

[bholley]

And this doesn't appear to be specific to the compositor thread. I can get this on the main thread with the following patch.

Patch: https://privatebin.net/?60d617c18ca8591a#ATMDFmo8b6geFUfDTzNLsMdoCALCtJBq1B+l3PoNZOQ=
.mozconfig: https://privatebin.net/?1ae7b6e29352fcdc#4fmF7Rd+37hQgjHurJn183aMszEtWTrih9Y6r8jHsDs=