I encounter a problem that use clang/libc++/libc++abi only to build the whole system(As i remeber gcc should be ok).
In firefox, there is a system_wrapper header include sched.h, but in hunspell codes, calloc and free was redefined, so there is a conflicts here.
for example, in "extensions/spellcheck/hunspell/src/hunspell_alloc_hooks.h"
#define calloc(count, size) HunspellAllocator::CountingCalloc(count, size)
It's not a big issue and can be fixed in firefox.
but still feel strange that these declarations exists in sched.h and also a little bit conflict with common sense.
Please consider it.