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