[better_errors][1] is a Rack middleware that replaces the default standard rails error page with a more useful one. The default Rails error page is also useful, but there is so much output that we don’t usually need and also there is a lot of other things we might need to see. The features of better_errors gem are awesome: Full stack trace Source code inspection for all stack frames (with highlighting) Local and instance variable inspection Live REPL (Read-Eval-Print Loop) on every stack frame In this local and instance variable inspection is so useful. We can immediately