} else {
		f.Go.Version = version
		f.Syntax.updateLine(f.Go.Syntax, "go", version)
	}
	return nil
}

func (f *WorkFile) AddToolchainStmt(name string) error {
	if !ToolchainRE.MatchString(name) {
		return fmt.Errorf("invalid toolchain name %q", name)
	}
	if f.Toolchain == nil {
		stmt := &Line{Token: []string{"toolchain", name}}

			base.Fatalf("go: internal error: %v", err)
		}
	}
	if *editToolchain == "none" {
		workFile.DropToolchainStmt()
	} else if *editToolchain != "" {
		if err := workFile.AddToolchainStmt(*editToolchain); err != nil {
			base.Fatalf("go: internal error: %v", err)
		}
	}

	if len(workedits) > 0 {
		for _, edit := range workedits {
			edit(workFile)
		}
	}

			base.Fatalf("go: internal error: %v", err)
		}
	}
	if *editToolchain == "none" {
		modFile.DropToolchainStmt()
	} else if *editToolchain != "" {
		if err := modFile.AddToolchainStmt(*editToolchain); err != nil {
			base.Fatalf("go: internal error: %v", err)
		}
	}

	if len(edits) > 0 {
		for _, edit := range edits {
			edit(modFile)
		}
	}
	modFile.SortBlocks()

	// which will not understand the toolchain line.
	if toolchain == "go"+goVers || gover.Compare(gover.FromToolchain(toolchain), gover.GoStrictVersion) < 0 {
		wf.DropToolchainStmt()
	} else {
		wf.AddToolchainStmt(toolchain)
	}
	return true
}

// UpdateWorkFile updates comments on directory directives in the go.work
// file to include the associated module path.
func UpdateWorkFile(wf *modfile.WorkFile) {

func (f *File) DropToolchainStmt() {
	if f.Toolchain != nil {
		f.Toolchain.Syntax.markRemoved()
		f.Toolchain = nil
	}
}

func (f *File) AddToolchainStmt(name string) error {
	if !ToolchainRE.MatchString(name) {
		return fmt.Errorf("invalid toolchain name %q", name)
	}
	if f.Toolchain == nil {
		var hint Expr
		if f.Go != nil && f.Go.Syntax != nil {