How to edit a native build system in Sublime Text 2?

Question

Ok this is very trivial question, but just cannot find answer anywhere.

I know there must be a JSON file with all the build systems somewhere, but I just cannot find

Answer 1

Here is the doc on ST2 build systems

The Ruby build file, for instance, is located here:

~/Library/Application Support/Sublime Text 2/Packages/Ruby/Ruby.sublime-build