cc -pthread  -Wall -Wextra -Werror -Wno-error=deprecated -Wno-error=deprecated-declarations unistd/_Fork.c -o unistd/_Fork -D_POSIX_C_SOURCE=202405L  -lm -lpthread  -liconv
unistd/_Fork.c:5:22: error: use of undeclared identifier '_Fork'
    5 | pid_t (*foo)(void) = _Fork;
      |                      ^
1 error generated.