Summary:
When an operation fails, we have an error message. This was being displayed in the diagnostic screen output, but not included in the debug log.
This makes them both have same bahaviour, so they both include the error messages.
Reviewed By: passy
Differential Revision: D17181847
fbshipit-source-id: 823f73d641d2315da86a0019479716852950f9a5