wsl ubuntu18.04 默认的cmake为3.10，编译CMakeLists.txt经常需要高版本cmake。
升级过程如下：
下载cmake-3.15.3-Linux-x86_64.tar.gz
wget https://cmake.org/files/v3.15/cmake-3.15.3-Linux-x86_64.tar.gz
解压文件
tar zxvf cmake-3.15.3-Linux-x86_64.tar.gz
查看解压文件
tree -L 2 cmake-3.15.3-Linux-x86_64
tree -L 2 cmake-3.15.3-Linux-x86_64
cmake-3.15.3-Linux-x86_64
├── bin
│ ├── ccmake
│ ├── cmake
│ ├── cmake-gui
│ ├── cpack
│ └── ctest
├── doc
│ └── cmake
├── man
│ ├── man1
│ └── man7
└── share
├── aclocal
├── applications
├── cmake-3.15
├── icons
└── mime
创建软链接
sudo mv cmake-3.15.3-Linux-x86_64 /opt/cmake-3.15.3
sudo ln -sf /opt/cmake-3.15.3/bin/* /usr/bin/
查看cmake版本
cmake --version
cmake version 3.15.3
CMake suite maintained and supported by Kitware (kitware.com/cmake).
