clang -O2  -Wall -Wextra -Werror -Wno-error=deprecated -Wno-error=deprecated-declarations semaphore/sem_clockwait.c -o semaphore/sem_clockwait -D_POSIX_C_SOURCE=202405L  -lm  -lintl
semaphore/sem_clockwait.c:5:75: error: use of undeclared identifier 'sem_clockwait'
int (*foo)(sem_t *restrict, clockid_t, const struct timespec *restrict) = sem_clockwait;
                                                                          ^
1 error generated.