cc -pipe -O   -pthread  -Wall -Wextra -Werror -Wno-error=deprecated -Wno-error=deprecated-declarations threads/ONCE_FLAG_INIT.c -o threads/ONCE_FLAG_INIT -D_POSIX_C_SOURCE=202405L  -lm -lpthread -lrt  -lrt -lcrypt
threads/ONCE_FLAG_INIT.c:1:10: fatal error: threads.h: No such file or directory
 #include <threads.h>
          ^~~~~~~~~~~
compilation terminated.