listCmd.Env = append(os.Environ(), "GO111MODULE=on")

	var (
		cmdEnv  []string
		modArgs []string
	)
	if out, err := listCmd.Output(); err == nil && string(bytes.TrimSpace(out)) == "std" {
		// Force module mode to use mkwinsyscall at the same version as the x/sys
		// module vendored into the standard library.
		cmdEnv = append(os.Environ(), "GO111MODULE=on")

	`,
}

func init() {
	CmdEnv.Run = runEnv // break init cycle
	base.AddChdirFlag(&CmdEnv.Flag)
	base.AddBuildFlagsNX(&CmdEnv.Flag)
}

var (
	envJson    = CmdEnv.Flag.Bool("json", false, "")
	envU       = CmdEnv.Flag.Bool("u", false, "")
	envW       = CmdEnv.Flag.Bool("w", false, "")
	envChanged = CmdEnv.Flag.Bool("changed", false, "")
)

func MkEnv() []cfg.EnvVar {

	// but in practice there might be skew
	// This makes sure we all agree.
	cfg.OrigEnv = toolchain.FilterEnv(os.Environ())
	cfg.CmdEnv = envcmd.MkEnv()
	for _, env := range cfg.CmdEnv {
		if os.Getenv(env.Name) != env.Value {
			os.Setenv(env.Name, env.Value)
		}
	}

	cmd.Flag.Usage = func() { cmd.Usage() }
	if cmd.CustomFlags {
		args = args[1:]
	} else {

}

// OrigEnv is the original environment of the program at startup.
var OrigEnv []string

// CmdEnv is the new environment for running go tool commands.
// User binaries (during go test or go run) are run with OrigEnv,
// not CmdEnv.
var CmdEnv []EnvVar

var envCache struct {
	once   sync.Once
	m      map[string]string
	goroot map[string]string
}

`)
	xexit(2)
}

// commands records the available commands.
var commands = map[string]func(){
	"banner":    cmdbanner,
	"bootstrap": cmdbootstrap,
	"clean":     cmdclean,
	"env":       cmdenv,
	"install":   cmdinstall,
	"list":      cmdlist,
	"test":      cmdtest,
	"version":   cmdversion,
}

// main takes care of OS-specific startup and dispatches to xmain.
func main() {

		// Remove distribution packages.
		xremoveall(pathf("%s/pkg/distpack", goroot))
	}
}

/*
 * command implementations
 */

// The env command prints the default environment.
func cmdenv() {
	path := flag.Bool("p", false, "emit updated PATH")
	plan9 := flag.Bool("9", gohostos == "plan9", "emit plan 9 syntax")
	windows := flag.Bool("w", gohostos == "windows", "emit windows syntax")
	xflagparse(0)