$ wget https://github.com/downloads/libevent/libevent/libevent-2.0.21-stable.tar.gz
$ tar zxf libevent-2.0.21-stable.tar.gz
$ cd libevent-2.0.21-stable
$ ./configure
$ make
$ sudo make install
$ su -
# echo /usr/local/lib > /etc/ld.so.conf.d/libevent.conf
# ldconfig
# exit
$ wget http://downloads.sourceforge.net/tmux/tmux-1.8.tar.gz
$ tar zxf tmux-1.8.tar.gz
$ cd tmux-1.8
$ ./configure
$ make
$ sudo make install