// version of the form "v1.2.3". Go versions may also include spaces and
// special characters.
func ProgramInfo(info *debug.BuildInfo) (goVers, progPath, progVers string) {
	goVers = info.GoVersion
	if strings.Contains(goVers, "devel") || strings.Contains(goVers, "-") {
		goVers = "devel"
	}

	progPath = info.Path
	if progPath == "" {
		progPath = strings.TrimSuffix(filepath.Base(os.Args[0]), ".exe")
	}

				if isGoBinaryCandidate(file, info) {
					fmt.Fprintf(os.Stderr, "%s: %v\n", file, err)
				}
			}
		}
		return
	}

	fmt.Printf("%s: %s\n", file, bi.GoVersion)
	bi.GoVersion = "" // suppress printing go version again
	mod := bi.String()
	if *versionM && len(mod) > 0 {
		fmt.Printf("\t%s\n", strings.ReplaceAll(mod[:len(mod)-1], "\n", "\n\t"))
	}

	// determine Go version for each file
	for _, file := range check.files {
		// use unaltered Config.GoVersion by default
		// (This version string may contain dot-release numbers as in go1.20.1,
		// unlike file versions which are Go language versions only, if valid.)
		v := check.conf.GoVersion

		fileVersion := asGoVersion(file.GoVersion)
		if fileVersion.isValid() {
			// use the file version, if applicable

						break
					}
					const prefix = "-lang="
					if strings.HasPrefix(arg, prefix) {
						goVersion = arg[len(prefix):]
					}
				}
			}
		}

		// parse and type-check file
		file, err := parser.ParseFile(fset, filename, nil, 0)
		if err == nil {
			conf := Config{
				GoVersion: goVersion,
				Importer:  stdLibImporter,
			}
			_, err = conf.Check(filename, fset, []*ast.File{file}, nil)
		}

					vars = append(vars, obj)
				}
			}
		}
		var body *ast.BlockStmt
		switch n := n.(type) {
		case *ast.File:
			// Only traverse the file if its goversion is strictly before go1.22.
			goversion := versions.FileVersion(pass.TypesInfo, n)
			return versions.Before(goversion, versions.Go1_22)
		case *ast.RangeStmt:
			body = n.Body
			addVar(n.Key)
			addVar(n.Value)
		case *ast.ForStmt:
			body = n.Body

					const prefix = "-lang="
					if strings.HasPrefix(arg, prefix) {
						goVersion = arg[len(prefix):]
					}
				}
			}
		}

		// parse and type-check file
		if testing.Verbose() {
			fmt.Println("\t", filename)
		}
		file, err := syntax.ParseFile(filename, nil, nil, 0)
		if err == nil {
			conf := Config{
				GoVersion: goVersion,
				Importer:  stdLibImporter,
			}

! stderr .+

# go env -w rejects unknown or bad variables
! go env -w GOGC=off
stderr 'unknown go command variable GOGC'
! go env -w GOEXE=.bat
stderr 'GOEXE cannot be modified'
! go env -w GOVERSION=customversion
stderr 'GOVERSION cannot be modified'
! go env -w GOENV=/env
stderr 'GOENV can only be set using the OS environment'
! go env -w GODEBUG=gctrace=1
stderr 'GODEBUG can only be set using the OS environment'

	Dir        string           `json:",omitempty"` // directory holding local copy of files, if any
	GoMod      string           `json:",omitempty"` // path to go.mod file describing module, if any
	GoVersion  string           `json:",omitempty"` // go version used in module
	Retracted  []string         `json:",omitempty"` // retraction information, if any (with -retracted or -u)

	// they do not belong to any package.
	//
	// See cmd/compile/internal/base/link.go:ReservedImports variable.
	if s.goVersion >= ver120 && (strings.HasPrefix(name, "go:") || strings.HasPrefix(name, "type:")) {
		return ""
	}

	// For go1.18 and below, the prefix are "type." and "go." instead.
	if s.goVersion <= ver118 && (strings.HasPrefix(name, "go.") || strings.HasPrefix(name, "type.")) {
		return ""
	}

	goversion := fmt.Sprintf("go1.%d", goversion.Version)
	for _, v := range []string{
		goversion,
		goversion + ".0",
		goversion + ".1",
		goversion + ".rc",
	} {
		conf := Config{GoVersion: v}
		pkg := mustTypecheck("package p", &conf, nil)
		if pkg.GoVersion() != conf.GoVersion {
			t.Errorf("got %s; want %s", pkg.GoVersion(), conf.GoVersion)
		}
	}
}