err = errors.New("warning promoted to error")
	}

	return sh.reportCmd("", "", output, err)
}

// gccld runs the gcc linker to create an executable from a set of object files.
// Any error output is only displayed for BuildN or BuildX.
func (b *Builder) gccld(a *Action, objdir, outfile string, flags []string, objs []string) error {
	p := a.Package
	sh := b.Shell(a)
	var cmd []string

	if err != nil {
		Exitf("running %s failed: %v\n%s\n%s", argv[0], err, cmd, out)
	}

	// Filter out useless linker warnings caused by bugs outside Go.
	// See also cmd/go/internal/work/exec.go's gccld method.
	var save [][]byte
	var skipLines int
	for _, line := range bytes.SplitAfter(out, []byte("\n")) {
		// golang.org/issue/26073 - Apple Xcode bug

C,GAAI,GACJ7L,EAAG,GACH8L,IAAK,CAAC,MAAO,MAAO,QAAS,QAAS,UACtCC,GAAI,GACJC,GAAI,GACJC,EAAG,GACHC,IAAK,GACLC,EAAG,GACHC,MAAO,GACPC,KAAM,GACNC,IAAK,GACLC,IAAK,GACLC,OAAQ,GACRC,EAAG,GACHC,GAAI,IAQAC,GAAmB,8DAOnBC,GAAmB,sIAyBlB,SAASC,GAAaC,EAAYC,EAAWC,GAClD,GAA0B,IAAtBF,EAAWzQ,OACb,OAAOyQ,EAGT,GAAIE,GAAoC,mBAAfA,EACvB,OAAOA,EAAWF,GAQpB,IALA,IACMG,GADY,IAAI9R,OAAO+R,WACKC,gBAAgBL,EAAY,aACxDM,EAAgBla,OAAOma,KAAKN,GAC5B3C,EAAW,GAAGxM,MAAMvK,KAAK4Z,EAAgB1I,KAAKhH,iBAAiB,MAZP+P,EAAA,SAcrDtN,EAAOC,GACd,IAA...

C,GAAI,GACJrT,EAAG,GACHsT,IAAK,CAAC,MAAO,MAAO,QAAS,QAAS,UACtCC,GAAI,GACJC,GAAI,GACJC,EAAG,GACHC,IAAK,GACLC,EAAG,GACHC,MAAO,GACPC,KAAM,GACNC,IAAK,GACLC,IAAK,GACLC,OAAQ,GACRC,EAAG,GACHC,GAAI,IAQAC,GAAmB,8DAOnBC,GAAmB,sIAyBlB,SAASC,GAAaC,EAAYC,EAAWC,GAClD,GAA0B,IAAtBF,EAAWpU,OACb,OAAOoU,EAGT,GAAIE,GAAoC,mBAAfA,EACvB,OAAOA,EAAWF,GAQpB,IALA,IACMG,GADY,IAAI7U,OAAO8U,WACKC,gBAAgBL,EAAY,aACxDM,EAAgBhb,OAAOib,KAAKN,GAC5B3C,EAAW,GAAG9R,MAAM/F,KAAK0a,EAAgBjJ,KAAKzL,iBAAiB,MAZP+U,EAAA,SAcrD9U,GACP,IAAM+U,EA...