Git supports the use of hooks in order to involve custom scripts when e.g. doing a commit. In our specific case, we use Ruby scripts and rely on a custom ruby build installed via rvm.
Unfortunately when using SourceTree, the wrong ruby version is always being picked as well as the wrong gem path.

Currently the app does not apply any settings defined in the .profile or other configuration files.
Since OS X 10.8 no longer supports the environment.plist file, applications themselves seem to be responsible to read custom variables.

It would be nice to be able to define custom environmental variables within the app, or be able to read in configuration files like .profile