cc -pthread  -Wall -Wextra -Werror -Wno-error=deprecated -Wno-error=deprecated-declarations unistd/_SC_V7_LP64_OFF64.c -o unistd/_SC_V7_LP64_OFF64 -D_POSIX_C_SOURCE=202405L  -lm -lpthread  -liconv
unistd/_SC_V7_LP64_OFF64.c:3:17: error: use of undeclared identifier '_SC_V7_LP64_OFF64'
    3 | int const foo = _SC_V7_LP64_OFF64;
      |                 ^
1 error generated.