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)
		}
	}
}

		}
		files = append(files, f)
	}
	tc := &types.Config{
		Importer:  makeTypesImporter(cfg, fset),
		Sizes:     types.SizesFor("gc", build.Default.GOARCH), // TODO(adonovan): use cfg.Compiler
		GoVersion: cfg.GoVersion,
	}
	info := &types.Info{
		Types:      make(map[ast.Expr]types.TypeAndValue),
		Defs:       make(map[*ast.Ident]types.Object),
		Uses:       make(map[*ast.Ident]types.Object),

        GOPROXY="https://proxy.golang.org,direct"
        GOROOT="/usr/local/go"
        GOSUMDB="sum.golang.org"
        GOTMPDIR=""
        GOTOOLDIR="/usr/local/go/pkg/tool/darwin_arm64"
        GOVCS=""
        GOVERSION="go1.20.7"
        GCCGO="gccgo"
        AR="ar"
        CC="clang"
        CXX="clang++"
        CGO_ENABLED="1"
        GOMOD="/dev/null"
        GOWORK=""
        CGO_CFLAGS="-O2 -g"

# Unsupported go versions should be rejected, since we don't know
# what versions they would report.
! go mod graph -go=1.99999999999
stderr '^invalid value "1\.99999999999" for flag -go: maximum supported Go version is '$goversion'\nusage: go mod graph \[-go=version\] \[-x\]\nRun ''go help mod graph'' for details.$'


-- go.mod --
// Module m indirectly imports a package from
// example.com/retract/incompatible. Its selected version of