noob problem with emerge gnome-libs

[NatureBoy2]

I'm running into a problem emerging gnome-libs. It stops every time with these errors:

/usr/lib/libesd.so: undefined reference to `pthread_create'
/usr/lib/libesd.so: undefined reference to `dlclose'
/usr/lib/libesd.so: undefined reference to `dlopen'
/usr/lib/libesd.so: undefined reference to `dlsym'
/usr/lib/libesd.so: undefined reference to `pthread_mutex_trylock'
/usr/lib/libesd.so: undefined reference to `pthread_join'
collect2: ld returned 1 exit status

Can anyone give me a pointer about what might be wrong, or what approach I can take to try to fix this?

Thanks!