Build Issues with Virtual Box 4.18 host /Ubuntu 11.10 64-bit

[simon.ponder]

Anybody else getting errors like this building pete's code from his github for NS4G? I keep getting this with a make -j8 on a 4 core virtual.

out/host/linux-x86/obj/STATIC_LIBRARIES/libLLVMSupport_intermediates/libLLVMSupport.a(Mutex.o): In function `llvm::sys::MutexImpl::tryacquire()':
/home/simon/android/external/llvm/lib/Support/Mutex.cpp:143: undefined reference to `pthread_mutex_trylock'
collect2: ld returned 1 exit status
make: *** [out/host/linux-x86/obj/EXECUTABLES/test-librsloader_intermediates/test-librsloader] Error 1
make: *** Waiting for unfinished jobs....
true
true
true

For what its worth, I get the same error without the j parameter.