Check if Vim is compiled with Python or Ruby:
λ vim --version | ack '(python|ruby)'
Remove Vim version installed with apt-get
if present:
λ sudo apt-get remove vim-common vim-runtime
Install dependencies needed to compile Vim:
λ sudo apt-get build-dep vim
Install Mercurial:
λ sudo apt-get install mercurial
Clone Vim repository, compile it and install the new version:
λ hg clone https://vim.googlecode.com/hg/ vim
λ cd vim
λ ./configure --enable-pythoninterp --enable-rubyinterp
λ make
λ sudo make install