error: unpack failed: error Missing tree

最近新建一个仓库，push时遇到如下问题，试了好多方法，最后在stackoverflow上找到解决办法了，可是在开始时就试过这方法，但不成。至于为嘛出现的这种错误，还是不明白原因。

git.exe push --progress  "origin" release:refs/for/release%r=xxx

Counting objects: 3, done.
Delta compression using up to 4 threads.
Compressing objects: 100% (3/3), done.
Writing objects: 100% (3/3), 663 bytes | 0 bytes/s, done.
Total 3 (delta 0), reused 0 (delta 0)
error: unpack failed: error Missing tree 4201fba85e02299e016f0129621858ec21ac94ae
To (url)
! [remote rejected] release -> refs/for/release%r=xxx(n/a (unpacker error))
error: failed to push some refs to ‘(url)‘

git did not exit cleanly (exit code 1) (593 ms @ 2015/5/15 9:51:12)

解决方法：git push --no-thin origin HEAD:refs/for/release

Git还得花时间研究下，刚接触不久，小菜鸟一枚，好多原理都还弄不明白