參考 @Leedy 和 @依雲 的答案, 找出有個 unshallow 參數:

git fetch --help


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

（你們就在評論裡解決問題了？）

$ 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.
...

可見 git shallow clone 只能 clone 當前 remote/HEAD 的目錄結構，不包括歷史，因此不是完整的 repo。

However，Git 1.9/2.0 已經去除了這個限制，請參閱 https://github.com/git/git/commit/82fba2b9d39163a0c9b7a3a2f35964cbc039e1a。

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

雷雷

--深度=

使用 --depth= 選項（請參閱 git-clone(1)）加深或縮短由 git clone 建立的淺儲存庫的歷史記錄，以從每個遠端分支歷史記錄的提示開始指定的提交次數。未取得加深提交的標籤。

git fetch --depth=1000000

stackoverflow上看到個解決辦法，但我嘗試後還是不好使。
http://stackoverflow.com/questions/6802145/convert-shallow-clone-to-full-clone

git pull --unshallow