cc -pthread  -Wall -Wextra -Werror -Wno-error=deprecated -Wno-error=deprecated-declarations unistd/_POSIX2_SYMLINKS.c -o unistd/_POSIX2_SYMLINKS -D_POSIX_C_SOURCE=202405L -lm -lpthread -lnetwork -lbsd -latomic
unistd/_POSIX2_SYMLINKS.c:3:17: error: '_POSIX2_SYMLINKS' undeclared here (not in a function)
    3 | int const foo = _POSIX2_SYMLINKS;
      |                 ^~~~~~~~~~~~~~~~