airbrake/airbrake — pull request #265 by dvdplm (2013-12-30 13:28:30+00:00)
Title: Support nested exceptions

Support the nested exceptions feature of Ruby 2.1 (Exception#cause) in a backwards compatible way (i.e. without breaking anything).
Implies a pretty big refactoring of how the Notice class renders exception(s) and tries to untangle the various custom options to notice creation from the actual exceptions.