Private method `warn' called for class ActiveSupport::Deprecation

[henryaj]

Describe the bug
Getting a NoMethodError coming from the library when running Rails 7.2.

Full stacktrace:

NoMethodError: private method `warn' called for class ActiveSupport::Deprecation (NoMethodError)

        ActiveSupport::Deprecation.warn('The total_columns_width configuration option is deprecated and has no effect.')
                                  ^^^^^
/home/runner/_work/mast/mast/vendor/bundle/ruby/3.3.0/gems/rails_admin-3.3.0/lib/rails_admin/config.rb:287:in `total_columns_width='
/home/runner/_work/mast/mast/config/initializers/rails_admin.rb:11:in `block in <main>'
/home/runner/_work/mast/mast/vendor/bundle/ruby/3.3.0/gems/rails_admin-3.3.0/lib/rails_admin.rb:35:in `block in config'
/home/runner/_work/mast/mast/vendor/bundle/ruby/3.3.0/gems/rails_admin-3.3.0/lib/rails_admin/config/const_load_suppressor.rb:15:in `suppressing'
/home/runner/_work/mast/mast/vendor/bundle/ruby/3.3.0/gems/rails_admin-3.3.0/lib/rails_admin.rb:35:in `config'
/home/runner/_work/mast/mast/config/initializers/rails_admin.rb:1:in `<main>'
/home/runner/_work/mast/mast/vendor/bundle/ruby/3.3.0/gems/railties-7.2.2.1/lib/rails/engine.rb:689:in `load'
/home/runner/_work/mast/mast/vendor/bundle/ruby/3.3.0/gems/railties-7.2.2.1/lib/rails/engine.rb:689:in `block in load_config_initializer'
/home/runner/_work/mast/mast/vendor/bundle/ruby/3.3.0/gems/activesupport-7.2.2.1/lib/active_support/notifications.rb:212:in `instrument'
/home/runner/_work/mast/mast/vendor/bundle/ruby/3.3.0/gems/railties-7.2.2.1/lib/rails/engine.rb:688:in `load_config_initializer'
/home/runner/_work/mast/mast/vendor/bundle/ruby/3.3.0/gems/railties-7.2.2.1/lib/rails/engine.rb:642:in `block (2 levels) in <class:Engine>'
/home/runner/_work/mast/mast/vendor/bundle/ruby/3.3.0/gems/railties-7.2.2.1/lib/rails/engine.rb:6[41](https://github.com/usemast/mast/actions/runs/14881913056/job/41791958761?pr=4418#step:15:42):in `each'
/home/runner/_work/mast/mast/vendor/bundle/ruby/3.3.0/gems/railties-7.2.2.1/lib/rails/engine.rb:641:in `block in <class:Engine>'
/home/runner/_work/mast/mast/vendor/bundle/ruby/3.3.0/gems/railties-7.2.2.1/lib/rails/initializable.rb:32:in `instance_exec'
/home/runner/_work/mast/mast/vendor/bundle/ruby/3.3.0/gems/railties-7.2.2.1/lib/rails/initializable.rb:32:in `run'
/home/runner/_work/mast/mast/vendor/bundle/ruby/3.3.0/gems/railties-7.2.2.1/lib/rails/initializable.rb:61:in `block in run_initializers'
/home/runner/_work/mast/mast/vendor/bundle/ruby/3.3.0/gems/railties-7.2.2.1/lib/rails/initializable.rb:50:in `each'
/home/runner/_work/mast/mast/vendor/bundle/ruby/3.3.0/gems/railties-7.2.2.1/lib/rails/initializable.rb:50:in `tsort_each_child'
/home/runner/_work/mast/mast/vendor/bundle/ruby/3.3.0/gems/railties-7.2.2.1/lib/rails/initializable.rb:60:in `run_initializers'
/home/runner/_work/mast/mast/vendor/bundle/ruby/3.3.0/gems/railties-7.2.2.1/lib/rails/application.rb:[43](https://github.com/usemast/mast/actions/runs/14881913056/job/41791958761?pr=4418#step:15:44)5:in `initialize!'
/home/runner/_work/mast/mast/config/environment.rb:5:in `<main>'

Reproduction steps
Use a deprecated configuration option like total_columns_width.

Expected behavior
A deprecation warning should be logged, and no error should occur.

[bashcoder]

This is because starting with Rails 7.2 you can no longer call ActiveSupport::Deprecation.warn() directly. Instead you have to create a new instance of a ActiveSupport::Deprecation object and then use it. Here's another issue from a different project that had the same issue. I tested commenting out all the instances in rails_admin and it now appears to work with rails-7.2.2.1.