Sometimes the OS barfs and refuses to generate signatures. When this happens, we have a hard time debugging. I just now got a report that signing on Mac failed. Fortunately, it went away on restart when I asked for --enable-logging. Unfortunately, it went away on restart when I asked for --enable-logging. --enable-logging is also a much more involved set of steps to ask the user to do.

It would be nice to route the OS error codes and such into NetLog.