Filed by: malexandru [at] mozilla.com
Parsed log: https://treeherder.mozilla.org/logviewer.html#?job_id=251161905&repo=autoland
Full log: https://queue.taskcluster.net/v1/task/d3bDgYgkSWy7Y8_HHHbNtA/runs/0/artifacts/public/logs/live_backing.log

16:03:17 INFO - mozcrash Copy/paste: /Users/cltbld/tasks/task_1560267682/build/macosx64-minidump_stackwalk /var/folders/kx/vjxn9xvj62q_mj4t8xyh3nm400000w/T/tmpSH7egQ.mozrunner/minidumps/944D521A-DDBD-45C3-8259-50749153EF45.dmp /Users/cltbld/tasks/task_1560267682/build/symbols
16:03:25 INFO - mozcrash Saved minidump as /Users/cltbld/tasks/task_1560267682/build/blobber_upload_dir/944D521A-DDBD-45C3-8259-50749153EF45.dmp
16:03:25 INFO - mozcrash Saved app info as /Users/cltbld/tasks/task_1560267682/build/blobber_upload_dir/944D521A-DDBD-45C3-8259-50749153EF45.extra
16:03:25 INFO - PROCESS-CRASH | Last test finished | application crashed [@ CheckIsMarkedThing<JSString*>(JSString**)]
16:03:25 INFO - Crash dump filename: /var/folders/kx/vjxn9xvj62q_mj4t8xyh3nm400000w/T/tmpSH7egQ.mozrunner/minidumps/944D521A-DDBD-45C3-8259-50749153EF45.dmp
16:03:25 INFO - Operating system: Mac OS X
16:03:25 INFO - 10.10.5 14F27
16:03:25 INFO - CPU: amd64
16:03:25 INFO - family 6 model 69 stepping 1
16:03:25 INFO - 4 CPUs
16:03:25 INFO -
16:03:25 INFO - GPU: UNKNOWN
16:03:25 INFO -
16:03:25 INFO - Crash reason: EXC_BAD_ACCESS / KERN_INVALID_ADDRESS
16:03:25 INFO - Crash address: 0xb8
16:03:25 INFO - Process uptime: 41 seconds
16:03:25 INFO -
16:03:25 INFO - Thread 0 (crashed)
16:03:25 INFO - 0 XUL!void CheckIsMarkedThing<JSString*>(JSString**) [Marking.cpp:b2cb7ee93eef1d56006716ed24f3d0c11e071f11 : 3284 + 0x75]
16:03:25 INFO - rax = 0x000000010e6e4a00 rdx = 0x0000000000000000
16:03:25 INFO - rcx = 0x0000000000000000 rbx = 0x00007fff5ad37658
16:03:25 INFO - rsi = 0x00000fad28500000 rdi = 0x000000010e612438
16:03:25 INFO - rbp = 0x00007fff5ad37610 rsp = 0x00007fff5ad37600
16:03:25 INFO - r8 = 0x0000000000001000 r9 = 0x000000012ea68000
16:03:25 INFO - r10 = 0x00000000000007d0 r11 = 0x000000012ea70000
16:03:25 INFO - r12 = 0x000000011341cc90 r13 = 0x00007fff5ad37658
16:03:25 INFO - r14 = 0x000000011341b000 r15 = 0x00007fff5ad37980
16:03:25 INFO - rip = 0x000000010b40620f
16:03:25 INFO - Found by: given as instruction pointer in context
16:03:25 INFO - 1 XUL!bool js::gc::IsAboutToBeFinalizedInternal<JSString>(JSString**) [Marking.cpp:b2cb7ee93eef1d56006716ed24f3d0c11e071f11 : 3389 + 0x5]
16:03:25 INFO - rbp = 0x00007fff5ad37640 rsp = 0x00007fff5ad37620
16:03:25 INFO - rip = 0x000000010b401622
16:03:25 INFO - Found by: previous frame's frame pointer
16:03:25 INFO - 2 XUL!js::AtomsTable::sweepIncrementally(js::AtomsTable::SweepIterator&, js::SliceBudget&) [JSAtom.cpp:b2cb7ee93eef1d56006716ed24f3d0c11e071f11 : 587 + 0x8]
16:03:25 INFO - rbp = 0x00007fff5ad37690 rsp = 0x00007fff5ad37650
16:03:25 INFO - rip = 0x000000010ae5f3c2
16:03:25 INFO - Found by: previous frame's frame pointer
16:03:25 INFO - 3 XUL!js::gc::GCRuntime::sweepAtomsTable(js::FreeOp*, js::SliceBudget&) [GC.cpp:b2cb7ee93eef1d56006716ed24f3d0c11e071f11 : 6160 + 0x12]
16:03:25 INFO - rbp = 0x00007fff5ad376d0 rsp = 0x00007fff5ad376a0
16:03:25 INFO - rip = 0x000000010b3d981b
16:03:25 INFO - Found by: previous frame's frame pointer
16:03:25 INFO - 4 XUL!sweepaction::SweepActionSequence<js::gc::GCRuntime*, js::FreeOp*, js::SliceBudget&>::run(js::gc::GCRuntime*, js::FreeOp*, js::SliceBudget&) [GC.cpp:b2cb7ee93eef1d56006716ed24f3d0c11e071f11 : 6489 + 0xf]
16:03:25 INFO - rbp = 0x00007fff5ad37710 rsp = 0x00007fff5ad376e0
16:03:25 INFO - rip = 0x000000010b43409b
16:03:25 INFO - Found by: previous frame's frame pointer
16:03:25 INFO - 5 XUL!sweepaction::SweepActionRepeatFor<js::gc::SweepGroupsIter, JSRuntime*, js::gc::GCRuntime*, js::FreeOp*, js::SliceBudget&>::run(js::gc::GCRuntime*, js::FreeOp*, js::SliceBudget&) [GC.cpp:b2cb7ee93eef1d56006716ed24f3d0c11e071f11 : 6549 + 0x1e]
16:03:25 INFO - rbp = 0x00007fff5ad37760 rsp = 0x00007fff5ad37720
16:03:25 INFO - rip = 0x000000010b43520c
16:03:25 INFO - Found by: previous frame's frame pointer

The priority flag is not set for this bug.
:jonco, could you have a look please?

For more information, please visit auto_nag documentation.

P5 unless this happens again.

Marking this as Resolved > Worksforme since there are no crashes for this signature in the past 6 months.