clang -O2  -Wall -Wextra -Werror -Wno-error=deprecated -Wno-error=deprecated-declarations dirent/alphasort.c -o dirent/alphasort -D_POSIX_C_SOURCE=202405L  -lm  -lintl
dirent/alphasort.c:5:62: error: use of undeclared identifier 'alphasort'
int (*foo)(const struct dirent **, const struct dirent **) = alphasort;
                                                             ^
1 error generated.