http://unix.stackexchange.com/questions/234691/how-to-fix-cannot-find-lxml2-error-while-installing-igraph-for-python sudo apt-get install libxml2 libxml2-dev zlib1g-dev
http://askubuntu.com/questions/733035/fatal-errorpython-h-no-such-file-or-directory sudo apt-get install python-all-dev