如何下载安卓源？

我想从android源码（Android的5.1.1_r9）的克隆，因为它是描述在这里。在 (Ubuntu 16.04) 终端中运行命令后，它不会下载任何内容。该文件夹保持为空。

nuwan2@nuwan:~/Desktop/workspace/original_sources$ repo init -u https://android.googlesource.com/platform/manifest -b android-5.1.1_r9
Get https://gerrit.googlesource.com/git-repo/clone.bundle
Get https://gerrit.googlesource.com/git-repo
remote: Finding sources: 100% (9/9)
remote: Total 9 (delta 1), reused 9 (delta 1)
Unpacking objects: 100% (9/9), done.
From https://gerrit.googlesource.com/git-repo
   c94d6eb..9ead97b  master     -> origin/master
Get https://android.googlesource.com/platform/manifest
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
  0     0    0     0    0     0      0      0 --:--:--  0:00:04 --:--:--     0
curl: (22) The requested URL returned error: 404 Not Found
Server does not provide clone.bundle; ignoring.
remote: Counting objects: 523, done        
remote: Total 5705 (delta 1529), reused 5705 (delta 1529)        
Receiving objects: 100% (5705/5705), 4.21 MiB | 248.00 KiB/s, done.
Resolving deltas: 100% (1529/1529), done.
From https://android.googlesource.com/platform/manifest
 * [new branch]      adt_23.0.3 -> origin/adt_23.0.3
 * [new branch]      afw-test-harness-1.5 -> origin/afw-test-harness-1.5
 * [new branch]      afw-test-harness-2.1 -> origin/afw-test-harness-2.1
 * [new branch]      afw-test-harness-marshmallow-dev -> origin/afw-test-harness-marshmallow-dev
 * [new branch]      afw-test-harness-nougat-dev -> origin/afw-test-harness-nougat-dev
 * [new branch]      android-1.6_r1 -> origin/android-1.6_r1
 * [new branch]      android-1.6_r1.1 -> origin/android-1.6_r1.1
 * [new branch]      android-1.6_r1.2 -> origin/android-1.6_r1.2
 * [new branch]      android-1.6_r1.3 -> origin/android-1.6_r1.3
 * [new branch]      android-1.6_r1.4 -> origin/android-1.6_r1.4
 * [new branch]      android-1.6_r1.5 -> origin/android-1.6_r1.5
 * [new branch]      android-1.6_r2 -> origin/android-1.6_r2

这个过程继续一系列的行，我不能把它们都粘贴在这里。最终结果如下。

 * [new tag]         webview-m40_r1 -> webview-m40_r1
 * [new tag]         webview-m40_r2 -> webview-m40_r2
 * [new tag]         webview-m40_r3 -> webview-m40_r3
 * [new tag]         webview-m40_r4 -> webview-m40_r4

Your identity is: Nuwan <[email protected]>
If you want to change this, please re-run 'repo init' with --config-name

repo has been initialized in /home/nuwan2/Desktop/workspace/original_sources
nuwan2@nuwan:~/Desktop/workspace/original_sources$
nuwan2@nuwan:~/Desktop/workspace/original_sources$ ls
nuwan2@nuwan:~/Desktop/workspace/original_sources$ 

而我的文件夹仍然是空的。什么地方出了错？将 android 源代码克隆到本地计算机的正确方法是什么。