if (vasprintf (&buf, fmt, ap) < 0)
if (_IO_vasprintf (&buf, fmt, ap) < 0)
__argp_error (const struct argp_state *state, const char *fmt, ...){  if (!state || !(state->flags & ARGP_NO_ERRS))    {      FILE *stream = state ? state->err_stream : stderr;      if (stream)	{	  va_list ap;#if _LIBC || (HAVE_FLOCKFILE && HAVE_FUNLOCKFILE)	  __flockfile (stream);#endif	  va_start (ap, fmt);#ifdef _LIBC	  char *buf;	  if (vasprintf (&buf, fmt, ap) < 0)	    buf = NULL;	  __fxprintf (stream, "%s: %s\n",		      state ? state->name : __argp_short_program_name (), buf);	  free (buf);#else	  fputs_unlocked (state ? state->name : __argp_short_program_name (),			  stream);	  putc_unlocked (':', stream);	  putc_unlocked (' ', stream);	  vfprintf (stream, fmt, ap);	  putc_unlocked ('\n', stream);#endif	  __argp_state_help (state, stream, ARGP_HELP_STD_ERR);	  va_end (ap);#if _LIBC || (HAVE_FLOCKFILE && HAVE_FUNLOCKFILE)	  __funlockfile (stream);#endif	}    }}