So you've finally lost your marbles and want to compile the latest version of phantomjs for yourself.
based on http://phantomjs.org/build.html
sudo apt-get install git build-essential g++ flex bison gperf ruby perl libsqlite3-dev libfontconfig1-dev libicu-dev libfreetype6 libssl-dev libpng-dev libjpeg-dev python libx11-dev libxext-dev ttf-mscorefonts-installer
git clone git://github.com/ariya/phantomjs.git
cd phantomjs
git checkout 2.1.1
git submodule init