repo sync android 5.0出错

repo sync android 5.0出错
none 0.0 0

下载代码mkl-mr1
repo init -u https://github.com/MoKee/android -b mkl-mr1

下列错误:
Checking out projects: 1% (8/540) platform/dalvik
Checking out projects: 2% (11/540) platform/developers/docs
error: Cannot checkout MoKee/android_development: ManifestInvalidRevisionError: revision refs/heads/mkl-mr1 in MoKee/android_development not found
error: in sync : revision refs/heads/mkl-mr1 in MoKee/android_development not found

请问如何解决?另外system_core也是同样错误

Android L 这么久远的版本,跑不过也很正常了…