安装libevent

# Install packages
$ sudo apt-get update && sudo apt-get install build-essential libssl-dev cmake -y

# Install Libevent
$ wget https://github.com/libevent/libevent/releases/download/release-2.1.8-stable/libevent-2.1.8-stable.tar.gz
$ tar -xzvf libevent-2.1.8-stable.tar.gz
$ cd libevent-2.1.8-stable
$ ./configure
$ make
$ sudo make install
$ sudo ldconfig -v