在安装YouCompleteMe插件的时候执行./install.py --tern-completer进行编译的时候，提示:

ERROR: some folders in /Users/wenci/.vim/bundle/YouCompleteMe/third_party/ycmd/third_party are empty; you probably forgot to run:
git submodule update --init --recursive

我执行git submodule update --init --recursive之后等了很久报错：

Cloning into '/Users/wenci/.vim/bundle/YouCompleteMe/third_party/ycmd/third_party/racerd'...
error: RPC failed; curl 56 SSLRead() return error -9806
fatal: The remote end hung up unexpectedly
fatal: early EOF
fatal: index-pack failed
fatal: clone of 'https://github.com/jwilm/racerd' into submodule path '/Users/wenci/.vim/bundle/YouCompleteMe/third_party/ycmd/third_party/racerd' failed
Failed to recurse into submodule path 'third_party/ycmd'

最开始我以为是网络问题，后来开了代理也是这样。似乎是某个第三方插件没办法 clone下来，网上查了一下似乎也没有解决办法。有人知道我这个是什么问题吗？

vim 版本：7.4.898
MacOS 版本：10.12