return gover.LocalToolchain()
		}
		if f.Toolchain != nil {
			return f.Toolchain.Name
		}
	}
	return "go" + mms.GoVersion()
}

func (mms *MainModuleSet) WorkFileReplaceMap() map[module.Version]module.Version {
	return mms.workFileReplaceMap
}

var MainModules *MainModuleSet

type Root int

const (
	// AutoRoot is the default for most commands. modload.Init will look for

	} else if MainModules.Contains(mod.Path) && mod.Version == "" {
		// Don't replace the workspace version of the main module.
		return module.Version{}, "", ""
	}
	if _, r, ok := replacement(mod, MainModules.WorkFileReplaceMap()); ok {
		return r, "", workFilePath
	}
	for _, v := range MainModules.Versions() {
		if index := MainModules.Index(v); index != nil {
			if from, r, ok := replacement(mod, index.replace); ok {