named `/godebug/non-default-behavior/<name>:events`
that counts the number of times a particular program's
behavior has changed based on a non-default value
for that setting.
For example, when `GODEBUG=http2client=0` is set,
`/godebug/non-default-behavior/http2client:events`
counts the number of HTTP transports that the program
has configured without HTTP/2 support.

## Default GODEBUG Values {#default}

# The -vv causes dist to print each build command as it runs.
# go tool dist clean cleans all directories, not just this one,
# but it's as close as we can get.

# Default target (first).
install:
	go tool dist install -v

verbose:
	go tool dist install -vv

clean:

	DIR="$( cd -P "$( dirname "$SOURCE" )" && pwd )"
	SOURCE="$(readlink "$SOURCE")"
	[[ $SOURCE != /* ]] && SOURCE="$DIR/$SOURCE"
done
DIR="$( cd -P "$( dirname "$SOURCE" )" && pwd )"

# Increase the V8 stack size from the default of 984K
# to 8192K to ensure all tests can pass without hitting
# stack size limits.

	for f2 := Format(1); f2 < formatMax; f2 <<= 1 {
		if f.has(f2) {
			ss = append(ss, formatNames[f2])
		}
	}
	switch len(ss) {
	case 0:
		return "<unknown>"
	case 1:
		return ss[0]
	default:
		return "(" + strings.Join(ss, " | ") + ")"
	}
}

// Magics used to identify various formats.
const (
	magicGNU, versionGNU     = "ustar ", " \x00"
	magicUSTAR, versionUSTAR = "ustar\x00", "00"

    description: Is this a new counter? See [config.txt](https://go.googlesource.com/telemetry/+/master/internal/configgen/config.txt) for the list of approved counters.
    options:
      - New
      - Update

	ctxt.Flag_maymorestack = flags.DebugFlags.MayMoreStack
	ctxt.Debugpcln = flags.DebugFlags.PCTab
	ctxt.IsAsm = true
	ctxt.Pkgpath = *flags.Importpath
	switch *flags.Spectre {
	default:
		log.Printf("unknown setting -spectre=%s", *flags.Spectre)
		os.Exit(2)
	case "":
		// nothing
	case "index":
		// known to compiler; ignore here so people can use

// the [Scanner.Scan] method will step through the 'tokens' of a file, skipping
// the bytes between the tokens. The specification of a token is
// defined by a split function of type [SplitFunc]; the default split
// function breaks the input into lines with line termination stripped. [Scanner.Split]
// functions are defined in this package for scanning a file into
// lines, bytes, UTF-8-encoded runes, and space-delimited words. The

// and the GODEBUG environment variable contains `zipinsecurepath=0`,
// OpenReader returns the reader with an ErrInsecurePath error.
// A future version of Go may introduce this behavior by default.
// Programs that want to accept non-local names can ignore
// the ErrInsecurePath error and use the returned reader.
func OpenReader(name string) (*ReadCloser, error) {
	f, err := os.Open(name)
	if err != nil {

// of the returned header to provide the full path name of the file.
// If compression is desired, callers should set the FileHeader.Method
// field; it is unset by default.
func FileInfoHeader(fi fs.FileInfo) (*FileHeader, error) {
	size := fi.Size()
	fh := &FileHeader{
		Name:               fi.Name(),
		UncompressedSize64: uint64(size),
	}
	fh.SetModTime(fi.ModTime())

	"strings"
	"sync"
	"testing"
)

var flagCheck = flag.Bool("check", false, "run API checks")

func TestMain(m *testing.M) {
	flag.Parse()
	for _, c := range contexts {
		c.Compiler = build.Default.Compiler
	}
	build.Default.GOROOT = testenv.GOROOT(nil)

	os.Exit(m.Run())
}

var (
	updateGolden = flag.Bool("updategolden", false, "update golden files")
)

func TestGolden(t *testing.T) {
	if *flagCheck {