var cc []string
		cc = append(cc, ctxt.extld()...)
		cc = append(cc, hostlinkArchArgs(ctxt.Arch)...)
		cc = append(cc, "--print-prog-name", "dsymutil")
		out, err := exec.Command(cc[0], cc[1:]...).CombinedOutput()
		if err != nil {
			Exitf("%s: finding dsymutil failed: %v\n%s", os.Args[0], err, out)
		}
		dsymutilCmd := strings.TrimSuffix(string(out), "\n")

		cc[len(cc)-1] = "strip"

	unitLengthOffset := lsu.Size()
	d.createUnitLength(lsu, 0) // unit_length (*), filled in at end
	unitstart = lsu.Size()
	lsu.AddUint16(d.arch, 2) // dwarf version (appendix F) -- version 3 is incompatible w/ XCode 9.0's dsymutil, latest supported on OSX 10.12 as of 2018-05
	headerLengthOffset := lsu.Size()
	d.addDwarfAddrField(lsu, 0) // header_length (*), filled in at end
	headerstart = lsu.Size()

	// cpos == unitstart + 4 + 2 + 4