We need to fix this. 729 MOZ_ASSERT(NS_IsMainThread()); (gdb) bt #0 0xb431af9a in pref_HashTableLookup (key=<optimized out>) at ../../../../modules/libpref/src/prefapi.cpp:729 #1 pref_HashTableLookup (key=0xb5b91bbe) at ../../../../modules/libpref/src/prefapi.cpp:726 #2 0xb431b07e in PREF_CopyCharPref (pref_name=<optimized out>, return_buffer=0xb2a5fbb0, get_default=<optimized out>) at ../../../../modules/libpref/src/prefapi.cpp:491 #3 0xb431cac2 in mozilla::Preferences::GetCString (aPref=0xb5b91bbe "memory_info_dumper.watch_fifo.directory", aResult=0xb2a5fc20) at ../../../../modules/libpref/src/Preferences.cpp:1374 #4 0xb42e2056 in (anonymous namespace)::FifoWatcher::OpenFd (this=<optimized out>) at ../../../xpcom/base/nsMemoryInfoDumper.cpp:405 #5 0xb42e0bcc in (anonymous namespace)::FdWatcher::StartWatching (this=0xb6a949c0) at ../../../xpcom/base/nsMemoryInfoDumper.cpp:223 #6 0xb42e0420 in DispatchToMethod<{anonymous}::FdWatcher, void ({anonymous}::FdWatcher::*)()> (method=&virtual (anonymous namespace)::FdWatcher::StartWatching(), obj=<optimized out>, arg=<optimized out>) at ../../../ipc/chromium/src/base/tuple.h:383 #7 RunnableMethod<{anonymous}::FdWatcher, void ({anonymous}::FdWatcher::*)(), Tuple0>::Run(void) (this=<optimized out>) at ../../../ipc/chromium/src/base/task.h:307

Is this something njn's team could take?

I'll take a look, can you point me to a an example of how this is handled elsewhere?

There is some refactoring work taking place over in bug 964636 that I think is related. Maybe that would be a good place to do it?

It's actually a dup of 980419. The patch in there already fixes this.