Show full_message if available

Author: k-tsj

lib/power_assert/context.rb

@@ -38,6 +38,9 @@ def initialize(base_caller_length)
           end
         rescue Exception => e
           warn "power_assert: [BUG] Failed to trace: #{e.class}: #{e.message}"
+          if e.respond_to?(:full_message)
+            warn e.full_message.gsub(/^/, 'power_assert:     ')
+          end
         end
       end
     end