     public init(
         path: AbsolutePath,
         provider: RepositoryProvider,
-        delegate: RepositoryManagerDelegate,
+        delegate: RepositoryManagerDelegate? = nil,
         fileSystem: FileSystem = localFileSystem
     ) {
         self.path = path


                    // Inform delegate.
                    self.callbacksQueue.async {
                        self.delegate.fetchingWillBegin(handle: handle)
                    }

                    // Fetch the repo.

    public let provider: RepositoryProvider

    /// The delegate interface.
    private let delegate: RepositoryManagerDelegate?

    /// The map of registered repositories.
    //
