Executed when installing the YouCompleteMe plug-in./install.py --tern-completerWhen compiling, prompt:

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

I do itgit submodule update --init --recursiveAfter waiting for a long time to report the error:

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'

At first, I thought it was a network problem, and then I opened an agent. It seems that a third-party plug-in can’t clone it down, and there seems to be no solution after checking it online. Does anyone know what my problem is?

Vim version:7.4.898
MacOS version:10.12