please note: this has changed to be DSL now.
`fatal true`

Before I say something wrong now --> /cc @jacknagel 

Related: Tex software will almost probably need the 
`env :userpaths` (which you can state directly in the body of the `TexInstalled` class now thanks to Jack.
If you want to be more precise, you can `def modify_build_environment; <your code here>; end` to specifically add only the paths and evironment variables needed for Tex.

Take a look at https://github.com/mxcl/homebrew/blob/master/Library/Homebrew/requirements.rb#L101