In any other context, `//go:debug` lines are ignored by the toolchain;
`go` `vet` reports such lines as misplaced.

## GODEBUG History {#history}

This section documents the GODEBUG settings introduced and removed in each major Go release
for compatibility reasons.
Packages or programs may define additional settings for internal debugging purposes;
for example,
see the [runtime documentation](/pkg/runtime#hdr-Environment_Variables)

	paxGNUSparseOffset    = "GNU.sparse.offset"
	paxGNUSparseNumBytes  = "GNU.sparse.numbytes"
	paxGNUSparseMap       = "GNU.sparse.map"
	paxGNUSparseName      = "GNU.sparse.name"
	paxGNUSparseMajor     = "GNU.sparse.major"
	paxGNUSparseMinor     = "GNU.sparse.minor"
	paxGNUSparseSize      = "GNU.sparse.size"
	paxGNUSparseRealSize  = "GNU.sparse.realsize"
)

// basicKeys is a set of the PAX keys for which we have built-in support.

			ModTime:  time.Unix(1392337404, 0),
			Typeflag: 0x30,
			Linkname: "",
			Uname:    "david",
			Gname:    "david",
			Devmajor: 0,
			Devminor: 0,
			PAXRecords: map[string]string{
				"GNU.sparse.major":    "1",
				"GNU.sparse.minor":    "0",
				"GNU.sparse.realsize": "200",
				"GNU.sparse.name":     "sparse-posix-1.0",
			},
			Format: FormatPAX,
		}, {
			Name:     "end",
			Mode:     420,

	// Identify the version of GNU headers.
	var is1x0 bool
	major, minor := hdr.PAXRecords[paxGNUSparseMajor], hdr.PAXRecords[paxGNUSparseMinor]
	switch {
	case major == "0" && (minor == "0" || minor == "1"):
		is1x0 = false
	case major == "1" && minor == "0":
		is1x0 = true
	case major != "" || minor != "":
		return nil, nil // Unknown GNU sparse PAX version

		// field directly themselves. All other approaches sets UTC.
		fh.ModifiedDate, fh.ModifiedTime = timeToMsDosTime(fh.Modified)

		// Use "extended timestamp" format since this is what Info-ZIP uses.
		// Nearly every major ZIP implementation uses a different format,
		// but at least most seem to be able to understand the other formats.
		//
		// This format happens to be identical for both local and central header

		}
	}
	if iosVer == "" || buildVer == "" {
		return "", errors.New("failed to parse ideviceinfo output")
	}
	verSplit := strings.Split(iosVer, ".")
	if len(verSplit) > 2 {
		// Developer images are specific to major.minor ios version.
		// Cut off the patch version.
		iosVer = strings.Join(verSplit[:2], ".")
	}
	sdkBase := "/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/DeviceSupport"