cc -O2 -pipe  -pthread -I/usr/local/include  -Wall -Wextra -Werror -Wno-error=deprecated -Wno-error=deprecated-declarations unistd/O_CLOFORK.c -o unistd/O_CLOFORK -D_POSIX_C_SOURCE=202405L  -lm -lpthread -L/usr/local/lib  -lintl
unistd/O_CLOFORK.c:2:17: error: use of undeclared identifier 'O_CLOFORK'
    2 | int const foo = O_CLOFORK;
      |                 ^
1 error generated.