// (It is not clear why package flag does not export this interface.)
type boolFlag interface {
	flag.Value
	IsBoolFlag() bool
}

// SetFromGOFLAGS sets the flags in the given flag set using settings in $GOFLAGS.
func SetFromGOFLAGS(flags *flag.FlagSet) {
	InitGOFLAGS()

	// This loop is similar to flag.Parse except that it ignores
	// unknown flags found in goflags, so that setting, say, GOFLAGS=-ldflags=-w

				cf.String(f.Name, "", "")
			}
		}
	}

	// Record the set of vet tool flags set by GOFLAGS. We want to pass them to
	// the vet tool, but only if they aren't overridden by an explicit argument.
	base.SetFromGOFLAGS(&CmdVet.Flag)
	addFromGOFLAGS := map[string]bool{}
	CmdVet.Flag.Visit(func(f *flag.Flag) {
		if isVetFlag[f.Name] {
			addFromGOFLAGS[f.Name] = true
		}
	})

		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 {
		base.SetFromGOFLAGS(&cmd.Flag)
		cmd.Flag.Parse(args[1:])
		flagCounterPrefix := "go/" + strings.ReplaceAll(cfg.CmdName, " ", "-") + "/flag"
		telemetry.CountFlags(flagCounterPrefix+":", cmd.Flag)

// to allow both
//
//	go test fmt -custom-flag-for-fmt-test
//	go test -x math
func testFlags(args []string) (packageNames, passToTest []string) {
	base.SetFromGOFLAGS(&CmdTest.Flag)
	addFromGOFLAGS := map[string]bool{}
	CmdTest.Flag.Visit(func(f *flag.Flag) {
		if short := strings.TrimPrefix(f.Name, "test."); passFlagToTest[short] {
			addFromGOFLAGS[f.Name] = true
		}
	})

		return false
	}

	if !modcacherwSeen && base.InGOFLAGS("-modcacherw") {
		fs := flag.NewFlagSet("goInstallVersion", flag.ExitOnError)
		fs.Var(modcacherwVal, "modcacherw", modcacherwFlag.Usage)
		base.SetFromGOFLAGS(fs)
	}

	// It would be correct to simply return true here, bypassing use
	// of the current go.mod or go.work, and let "go run" or "go install"
	// do the rest, including a toolchain switch.