clang -O2  -Wall -Wextra -Werror -Wno-error=deprecated -Wno-error=deprecated-declarations locale/getlocalename_l.c -o locale/getlocalename_l -D_POSIX_C_SOURCE=202405L  -lm  -lintl
locale/getlocalename_l.c:5:37: error: use of undeclared identifier 'getlocalename_l'
const char *(*foo)(int, locale_t) = getlocalename_l;
                                    ^
1 error generated.