Better Errors replaces the standard Rails error page with a much better and more useful error page. It is also usable outside of Rails in any Rack app as Rack middleware.
- Full stack trace
- Source code inspection for all stack frames (with highlighting)
- Local and instance variable inspection
- Live REPL on every stack frame
Add this to your Gemfile:
group :development do
gem "better_errors"
endNOTE: It is critical you put better_errors in the development section. Do NOT run better_errors in production, or on Internet facing hosts.
If you would like to use Better Errors' advanced features (REPL, local/instance variable inspection, pretty stack frame names), you need to add the binding_of_caller gem by @banisterfiend to your Gemfile:
gem "binding_of_caller"This is an optional dependency however, and Better Errors will work without it.
If you're using Rails, there's nothing else you need to do.
If you're not using Rails, you need to insert BetterErrors::Middleware into your middleware stack, and optionally set BetterErrors.application_root if you'd like Better Errors to abbreviate filenames within your application.
Here's an example using Sinatra:
require "sinatra"
require "better_errors"
configure :development do
use BetterErrors::Middleware
BetterErrors.application_root = File.expand_path("..", __FILE__)
end
get "/" do
raise "oops"
end- Supported
- MRI 1.9.2, 1.9.3
- JRuby (1.9 mode) - advanced features unsupported
- Rubinius (1.9 mode) - advanced features unsupported
- Coming soon
- MRI 2.0.0 - the official API for grabbing caller bindings is slated for MRI 2.0.0, but it has not been implemented yet
- Calling
yieldfrom the REPL segfaults MRI 1.9.x.
If you're using better_errors, I'd love to hear from you. Drop me a line and tell me what you think!
- Fork it
- Create your feature branch (
git checkout -b my-new-feature) - Commit your changes (
git commit -am 'Add some feature') - Push to the branch (
git push origin my-new-feature) - Create new Pull Request