What does it mean to install YouCompleteMe in vim?

Question

This problem occurred when I went to the root directory to execute ./install.sh. It ran for a long time after execution, and a lot of things were installed. Is this necessary?

Answer 1

This YCM is used to complete C/C++/C# code. If you don’t write these, you don’t need to install it

Answer 2

Try following YCM tips?
git submodule update --init --recursive
Then: ./install.py

Answer 3

ycm contains submodules, which were not downloaded when you git clone, so you need git colone --recursive https://github.com/Valloric/YouCompleteMe.git