I'm on AIX 6.1 TL07 SP03. I tried just "configure" (followed by "make") and the link failed to find the pthread routines such as pthread_mutexattr_init
I then added --enable-threads=posix but no change. Finally I did: export CFLAGS=-pthread and that worked. Before this, the link calls did not have -lpthread and the calls to the compiler did not have -pthread. I thought to be totally thread safe, you need both. Hope this helps someone, Perry Smith
