pkgs, err := ParseDir(fset, "./testdata/goversion", nil, 0)
	if err != nil {
		t.Fatal(err)
	}

	for _, p := range pkgs {
		want := strings.ReplaceAll(p.Name, "_", ".")
		if want == "none" {
			want = ""
		}
		for _, f := range p.Files {
			if f.GoVersion != want {
				t.Errorf("%s: GoVersion = %q, want %q", fset.Position(f.Pos()), f.GoVersion, want)
			}
		}
	}
}

	//     54  .  .  .  "main": *(obj @ 11)
	//     55  .  .  }
	//     56  .  }
	//     57  .  Unresolved: []*ast.Ident (len = 1) {
	//     58  .  .  0: *(obj @ 29)
	//     59  .  }
	//     60  .  GoVersion: ""
	//     61  }
}

func ExamplePreorder() {
	src := `
package p

func f(x, y int) {
	print(x + y)
}
`

	fset := token.NewFileSet()

	}
	info, ok := debug.ReadBuildInfo()
	if !ok {
		return nil, fmt.Errorf("no build info")
	}
	year, month, day := time.Now().UTC().Date()
	goVers := info.GoVersion
	// E.g.,  goVers:"go1.22-20240109-RC01 cl/597041403 +dcbe772469 X:loopvar"
	words := strings.Fields(goVers)
	goVers = words[0]
	progPkgPath := info.Path
	if progPkgPath == "" {

func LoadModGraph(ctx context.Context, goVersion string) (*ModuleGraph, error) {
	rs, err := loadModFile(ctx, nil)
	if err != nil {
		return nil, err
	}

	if goVersion != "" {
		v, _ := rs.rootSelected("go")
		if gover.Compare(v, gover.GoStrictVersion) >= 0 && gover.Compare(goVersion, v) < 0 {

		if data, err := os.ReadFile(filepath.Join(dir, "go.mod")); err == nil {
			goVersion := gover.GoModLookup(data, "go")
			if gover.Compare(goVersion, gover.Local()) > 0 {
				return "", &gover.TooNewError{What: mod.String(), GoVersion: goVersion}
			}
		} else if !errors.Is(err, fs.ErrNotExist) {
			return "", err
		}

		return dir, nil
	})
}

	err := check.newError(code)
	err.addf(at, format, args...)
	err.soft = true
	err.report()
}

func (check *Checker) versionErrorf(at poser, v goVersion, format string, args ...any) {
	msg := check.sprintf(format, args...)
	err := check.newError(UnsupportedFeature)
	err.addf(at, "%s requires %s or later", msg, v)
	err.report()
}

	TESTGO_GOROOT=<GOROOT used to build cmd/go, for use in tests that may change GOROOT>
	HOME=/no-home
	PATH=<actual PATH>
	TMPDIR=$WORK/tmp
	GODEBUG=<actual GODEBUG>
	devnull=<value of os.DevNull>
	goversion=<current Go version; for example, 1.12>

On Plan 9, the variables $path and $home are set instead of $PATH and $HOME.
On Windows, the variables $USERPROFILE and $TMP are set instead of
$HOME and $TMPDIR.

	err := check.newError(code)
	err.addf(at, format, args...)
	err.soft = true
	err.report()
}

func (check *Checker) versionErrorf(at positioner, v goVersion, format string, args ...any) {
	msg := check.sprintf(format, args...)
	err := check.newError(UnsupportedFeature)
	err.addf(at, "%s requires %s or later", msg, v)
	err.report()
}

		{Name: "GOTMPDIR", Value: cfg.Getenv("GOTMPDIR")},
		{Name: "GOTOOLCHAIN"},
		{Name: "GOTOOLDIR", Value: build.ToolDir},
		{Name: "GOVCS", Value: cfg.GOVCS},
		{Name: "GOVERSION", Value: runtime.Version()},
		{Name: "GODEBUG", Value: os.Getenv("GODEBUG")},
		{Name: "GOTELEMETRY", Value: telemetry.Mode()},
		{Name: "GOTELEMETRYDIR", Value: telemetry.Dir()},
	}

	for i := range env {

	if archive != "" {
		ofile = archive
	} else {
		out := "_go_.o"
		ofile = objdir + out
	}

	pkgpath := pkgPath(a)
	defaultGcFlags := []string{"-p", pkgpath}
	if p.Module != nil {
		v := p.Module.GoVersion
		if v == "" {
			v = gover.DefaultGoModVersion
		}
		if allowedVersion(v) {
			defaultGcFlags = append(defaultGcFlags, "-lang=go"+gover.Lang(v))
		}
	}
	if p.Standard {