gcc -pthread  -Wall -Wextra -Werror -Wno-error=deprecated -Wno-error=deprecated-declarations unistd/_CS_POSIX_V8_WIDTH_RESTRICTED_ENVS.c -o unistd/_CS_POSIX_V8_WIDTH_RESTRICTED_ENVS -D_POSIX_C_SOURCE=202405L -lm -lpthread -lrt -lxnet -lsocket -latomic
unistd/_CS_POSIX_V8_WIDTH_RESTRICTED_ENVS.c:2:17: error: ‘_CS_POSIX_V8_WIDTH_RESTRICTED_ENVS’ undeclared here (not in a function)
    2 | int const foo = _CS_POSIX_V8_WIDTH_RESTRICTED_ENVS;
      |                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~