cc -O2 -pthread -I/usr/local/include  -Wall -Wextra -Werror -Wno-error=deprecated -Wno-error=deprecated-declarations unistd/_PC_ASYNC_IO.c -o unistd/_PC_ASYNC_IO -D_POSIX_C_SOURCE=202405L  -lm -lpthread -lrt -L/usr/local/lib  -lintl -lcrypt
unistd/_PC_ASYNC_IO.c:2:17: error: '_PC_ASYNC_IO' undeclared here (not in a function)
    2 | int const foo = _PC_ASYNC_IO;
      |                 ^~~~~~~~~~~~