報錯如下：
bash: git-upload-pack: command not found
fatal: The remote end hung up unexpectedly
原因:原來代碼服務器上的git安裝路徑是/usr/local/git，不是默認路徑，根據提示，在git服務器上， 建立鏈接文件：
解決方法：
# ln -s /usr/local/git/bin/git-upload-pack /usr/bin/git-upload-pack
再次執行 git clone 成功！
報錯如下：
bash: git-receive-pack: command not found
fatal: Could not read from remote repository.
# ln -s /usr/local/git/bin/git-receive-pack /usr/bin/git-receive-pack