ref: baa5bfb2cc12a1dba2be5fff032d1fcf6cee49f7
dir: /sys/src/libc/9sys/werrstr.c/
#include <u.h>
#include <libc.h>
void
werrstr(char *fmt, ...)
{
va_list arg;
char buf[ERRMAX];
va_start(arg, fmt);
vseprint(buf, buf+ERRMAX, fmt, arg);
va_end(arg);
errstr(buf, ERRMAX);
}