clang -O2  -Wall -Wextra -Werror -Wno-error=deprecated -Wno-error=deprecated-declarations stdio/vfscanf.c -o stdio/vfscanf -D_POSIX_C_SOURCE=202405L  -lm  -lintl
stdio/vfscanf.c:5:61: error: implicitly declaring library function 'vfscanf' with type 'int (FILE *restrict, const char *restrict, __builtin_va_list)' [-Werror]
int (*foo)(FILE *restrict, const char *restrict, va_list) = vfscanf;
                                                            ^
stdio/vfscanf.c:5:61: note: include the header <stdio.h> or explicitly provide a declaration for 'vfscanf'
1 error generated.