Ruby – How to Uninstall from Source

debsums might help find stuff that was clandestinely overwritten by the source install...

I've not done much with Rails either, but I'd take a look in config/environments/production.rb to see what options there are for logging. Logging is usually done with the Logger standard ruby library which should just generate a log based on your current environment (eg log/production.log). You will get more events logged if you aren't in the production environment - production only logs info or above wheras other environments logs everything including debug. If you're getting exceptions in the application then take a look at Exceptional or New Relic.