clang -O2  -Wall -Wextra -Werror -Wno-error=deprecated -Wno-error=deprecated-declarations stdlib/getsubopt.c -o stdlib/getsubopt -D_POSIX_C_SOURCE=202405L  -lm  -lintl
stdlib/getsubopt.c:5:71: error: use of undeclared identifier 'getsubopt'
int (*foo)(char **restrict, char *const *restrict, char **restrict) = getsubopt;
                                                                      ^
1 error generated.