ubuntu18.04 卸载和重装cmake（uninstall and install cmake）
1. 卸载 cmake
sudo apt remove --purge cmake
hash -r
2 安装 cmake
两种方法snap或者源码安装
2.1 snap
sudo snap install cmake --classic
cmake --version #cmake version 3.17.2
2.2 source code
sudo apt install build-essential libssl-dev
wget https://github.com/Kitware/CMake/releases/download/v3.17.2/cmake-3.17.2.tar.gz
tar -zxvf cmake-3.17.2.tar.gz
cd cmake-3.17.2
./bootstrap
make
sudo make install