ref: d16188ee68ccb1cbfc976f015ac5e7a5caa72b05
dir: /sys/src/ape/lib/fmt/werrstr.c/
#include <stdarg.h> #include <errno.h> #include "fmt.h" extern char *_plan9err; void werrstr(const char *fmt, ...) { va_list arg; va_start(arg, fmt); snprint(_plan9err, 128, fmt, arg); va_end(arg); errno = EPLAN9; }