clang -O2  -Wall -Wextra -Werror=implicit-function-declaration sched/sched_yield.c -o sched/sched_yield -D_GNU_SOURCE -D_BSD_SOURCE -D_ALL_SOURCE -D_DEFAULT_SOURCE  -lm  -lintl
../out/minix/basic/sched/sched_yield.o: In function `main':
sched/sched_yield.c:(.text+0x2f7): undefined reference to `__libc_thr_yield'
clang: error: linker command failed with exit code 1 (use -v to see invocation)