When I get exceptions, it is often from deep within the call stack. When this happens, more often than not, the actual offending line of code is hidden from me:
One liner for callstack:
begin; Whatever.you.want; rescue => e; puts e.message; puts; puts e.backtrace; end
One liner for callstack without all the gems's:
begin; Whatever.you.want; rescue => e; puts e.message; puts; puts e.backtrace.grep_v(/\/gems\//); end
One liner for callstack without all the gems's and relative to current directory
begin; Whatever.you.want; rescue => e; puts e.message; puts; puts e.backtrace.grep_v(/\/gems\//).map { |l| l.gsub(`pwd`.strip + '/', '') }; end