cc -pthread  -Wall -Wextra -Werror -Wno-error=deprecated -Wno-error=deprecated-declarations unistd/_CS_V8_ENV.c -o unistd/_CS_V8_ENV -D_POSIX_C_SOURCE=202405L  -lm -lpthread  -liconv
unistd/_CS_V8_ENV.c:2:17: error: use of undeclared identifier '_CS_V8_ENV'
    2 | int const foo = _CS_V8_ENV;
      |                 ^
1 error generated.