cc -O2 -pthread  -Wall -Wextra -Werror=implicit-function-declaration unistd/_Fork.c -o unistd/_Fork -D_GNU_SOURCE -D_BSD_SOURCE -D_ALL_SOURCE -D_DEFAULT_SOURCE  -lm -lpthread -lrt  -lintl -lcrypt
unistd/_Fork.c: In function 'main':
unistd/_Fork.c:9:14: error: implicit declaration of function '_Fork' [-Werror=implicit-function-declaration]
    9 |  pid_t pid = _Fork();
      |              ^~~~~
cc1: some warnings being treated as errors