Installation | Ruby On Rails Debugbar

Require the `gem`

The debugbar is installed like any other gem. Add it to your Gemfile, then run bundle install to install it. As of today, you should only run the debugbar in development.

1group :development do
2  gem 'debugbar'
3end

Render the debugbar

With the ERB helper

In your layout, make sure the debugbar is rendered via the view helper.

 1<!DOCTYPE html>
 2<html>
 3  <head>
 4    ...
 5    <%= debugbar_head  if defined? Debugbar %> 
 6  </head>
 7 
 8  <body>
 9    ...
10    <%= debugbar_body if defined? Debugbar %> 
11  </body>
12</html>

Without the ERB helper

If your application doesn't use the erb view helper, you can render the debugbar manually. This can be useful if your frontend is an SPA and the shell isn't rendered by Rails.

In your index.html file, make sure the following code is added:

 1<!DOCTYPE html>
 2<html>
 3  <head>
 4    ...
 5    <script defer src="/_debugbar/assets/script"></script> 
 6  </head>
 7 
 8  <body>
 9 
10    <div id="__debugbar" data-turbo-permanent></div> 
11 
12    <!-- Optional configuration -->
13    <script type="text/javascript" data-turbo-permanent>
14      window._debugbarConfigOptions = {height: 300}
15    </script>
16  </body>
17</html>

Note that if you changed the route prefix in your configuration, you'll need to update the url in the script tag.

Puma configuration

It's recommended to run Puma in single mode! Rails use single mode by default in dev but if you modified it, set WEB_CONCURRENCY env var to 0. Puma cluster mode requires extra configuration.

Troubleshooting

If you run into any error, please open a GitHub issue with as much information as possible. There is also a dedicated Troubleshooting section.