cc -pthread  -Wall -Wextra -Werror=implicit-function-declaration sched/sched_getscheduler.c -o sched/sched_getscheduler -D_GNU_SOURCE -D_BSD_SOURCE -D_ALL_SOURCE -D_DEFAULT_SOURCE -lm -lpthread -lnetwork -lbsd -latomic
sched/sched_getscheduler.c: In function 'main':
sched/sched_getscheduler.c:10:22: error: implicit declaration of function 'sched_getscheduler' [-Werror=implicit-function-declaration]
   10 |         int policy = sched_getscheduler(0);
      |                      ^~~~~~~~~~~~~~~~~~
cc1: some warnings being treated as errors