On 23 March 2013 04:52, C.J. Adams-Collier KF7BMP wrote: > Thank you, Ian. I figured that it was built in to libgcc, and it looks > like my figuring was right: > > # strings /usr/lib/libgcc.a | grep pthread > pthread_create > pthread_getspecific > pthread_once > pthread_key_create > pthread_setspecific > pthread_create > pthread_mutex_unlock > pthread_mutex_lock This only says the library refers to those symbols, it doesn't say they're defined in that library. AFAIK GCC has never contained an implementation of pthreads, that should be provided by your OS libc.