cc -pthread  -Wall -Wextra -Werror -Wno-error=deprecated -Wno-error=deprecated-declarations sched/sched_setscheduler.c -o sched/sched_setscheduler -D_POSIX_C_SOURCE=202405L  -lm -lpthread  -liconv
sched/sched_setscheduler.c:6:19: error: expected identifier
    6 | int (*foo)(pid_t, int, const struct sched_param *) = sched_setscheduler;
      |                   ^
sched/sched_setscheduler.c:6:54: error: use of undeclared identifier 'sched_setscheduler'
    6 | int (*foo)(pid_t, int, const struct sched_param *) = sched_setscheduler;
      |                                                      ^
2 errors generated.