--- gc-7.6.0.orig/pthread_stop_world.c +++ gc-7.6.0/pthread_stop_world.c @@ -45,6 +45,7 @@ #include <semaphore.h> #include <errno.h> #include <unistd.h> +#include <sys/select.h> #include "atomic_ops.h" /* It's safe to call original pthread_sigmask() here. */