I initially thought that setting up Sencha Touch 2 to work under Linux would be pretty straightforward but it turned out to be a little cumbersome to install, what follows is a rundown of the steps that it took.
Download Sencha SDK Tools
Download the installer from http://www.sencha.com/products/sdk-tools/download/ , it comes in 32-bit and 64-bit.
$ uname -m x86_64 # 64-bit
Download Sencha Touch 2