参考 @Leedy 和 @依云 的答案, 找到有个 unshallow 参数:

git fetch --help


--unshallow
           Convert a shallow repository to a complete one, removing all the limitations imposed by shallow repositories.

（你们就在评论里解决问题了？）

$ git version
git version 1.8.5.3

$ git help clone
...
       --depth <depth>
           Create a shallow clone with a history truncated to the specified
           number of revisions. A shallow repository has a number of
           limitations (you cannot clone or fetch from it, nor push from nor
           into it), but is adequate if you are only interested in the recent
           history of a large project with a long history, and would want to
           send in fixes as patches.
...

可见 git shallow clone 只能 clone 当前 remote/HEAD 的目录结构，不包括历史，因此不是完整的 repo。

However，Git 1.9/2.0 已经去除了这个限制，见 https://github.com/git/git/commit/82fba2b9d39163a0c9b7a3a2f35964cbc039e1a。

参考：http://stackoverflow.com/questions/6941889/is-git-clone-depth-1-shallow-clone-more-useful-than-it-makes-out

$ git fetch --help

--depth=<depth>

Deepen or shorten the history of a shallow repository created by git clone with --depth= option (see git-clone(1)) to the specified number of commits from the tip of each remote branch history. Tags for the deepened commits are not fetched.

git fetch --depth=1000000

stackoverflow上看到个解决办法，但我尝试后还是不好使。
http://stackoverflow.com/questions/6802145/convert-shallow-clone-to-full-clone

git pull --unshallow