rails console by default boots with context.back_trace_limit=16, which can be changed to whatever you want simply by typing context.back_trace_limit=n. The problem is you have to type it each time you boot rails c. Where do I change the context.back_trace_limit permanently? Some more reading on rails console configuration appreciated.
You have to create/edit your ~/.irbrc with the following:
IRB.conf[:BACK_TRACE_LIMIT]= 20
To be taken into account:
- The options must be uppercased
- This option is changing not only the rails console, but the normal "irb" behavior (the rails console uses irb to run)
- This setting is global, and not per project
Reference http://rakeroutes.com/blog/customize-your-irb/
Update for Rails 5
In Rails 5 the command context.back_trace_limit=20 will fail.
In the console you need to use the command conf.back_trace_limit = 10 for the current session.
For permanent changes, writing IRB.conf[:BACK_TRACE_LIMIT]= 20 in your ~/.irbrc is still valid.
You can see the current settings by calling conf
来源：https://stackoverflow.com/questions/26295935/set-rails-console-stack-backtrace-limit-permanently