Debug B2G emulators no longer boot; they have this error on startup: 09:16:02 INFO - 12-16 17:05:59.291 719 719 I Gecko : ++DOMWINDOW == 5 (0x43e96930) [pid = 719] [serial = 5] [outer = 0x43e96390] 09:16:02 INFO - 12-16 17:06:00.461 673 697 I Gecko : [Parent 673] ###!!! ASSERTION: Should be on main thread.: 'NS_IsMainThread()', file ../../../gecko/gfx/layers/ipc/ShadowLayerUtilsGralloc.cpp, line 227 09:16:02 INFO - 12-16 17:06:00.582 719 719 D : HostConnection::get() New Host Connection established 0x44cff0d0, tid 719 09:16:02 INFO - 12-16 17:06:05.091 719 719 F MOZ_Assert: Assertion failure: false (MOZ_ASSUME_UNREACHABLE(unsupported relocation)), at ../../../gecko/js/src/jit/arm/Assembler-arm.cpp:767 09:16:02 INFO - 12-16 17:06:06.802 673 673 I Gecko : 09:16:02 INFO - 12-16 17:06:06.802 673 673 I Gecko : ###!!! [Parent][MessageChannel] Error: Channel error: cannot send/recv 09:16:02 INFO - 12-16 17:06:06.802 673 673 I Gecko : This is a regression that appeared sometime after Friday afternoon. full log: https://tbpl.mozilla.org/php/getParsedLog.php?id=32030413&tree=Pine&full=1

Right when we wanted to deploy all our debug tests :( Naveed can you help here? We have to back out / fix the regression asap. It seems like an arm assembler crash.

This looks like a duplicate of bug 950540.