Error when trying to upgrade rails admin from 2.0.2 to 3.0.0.beta

[estebanz01]

Describe the bug
Hello! 👋

I'm getting an error when trying to run the generator to migrate to rails_admin 3.0.0.beta with rails 6.0.4.4 and ruby 2.7.4.

          ?  Where do you want to mount rails_admin? Press <enter> for [admin] > admin
       route  mount RailsAdmin::Engine => '/admin', as: 'rails_admin'
      insert  config/initializers/rails_admin.rb
           -  Using [webpacker] for asset delivery method
Traceback (most recent call last):
        19: from bin/rails:4:in `<main>'
        18: from bin/rails:4:in `require'
        17: from /home/ubuntu/.rvm/gems/ruby-2.7.4@ark/gems/railties-6.0.4.4/lib/rails/commands.rb:18:in `<top (required)>'
        16: from /home/ubuntu/.rvm/gems/ruby-2.7.4@ark/gems/railties-6.0.4.4/lib/rails/command.rb:46:in `invoke'
        15: from /home/ubuntu/.rvm/gems/ruby-2.7.4@ark/gems/railties-6.0.4.4/lib/rails/command/base.rb:69:in `perform'
        14: from /home/ubuntu/.rvm/gems/ruby-2.7.4@ark/gems/thor-1.1.0/lib/thor.rb:392:in `dispatch'
        13: from /home/ubuntu/.rvm/gems/ruby-2.7.4@ark/gems/thor-1.1.0/lib/thor/invocation.rb:127:in `invoke_command'
        12: from /home/ubuntu/.rvm/gems/ruby-2.7.4@ark/gems/thor-1.1.0/lib/thor/command.rb:27:in `run'
        11: from /home/ubuntu/.rvm/gems/ruby-2.7.4@ark/gems/railties-6.0.4.4/lib/rails/commands/generate/generate_command.rb:26:in `perform'
        10: from /home/ubuntu/.rvm/gems/ruby-2.7.4@ark/gems/railties-6.0.4.4/lib/rails/generators.rb:276:in `invoke'
         9: from /home/ubuntu/.rvm/gems/ruby-2.7.4@ark/gems/thor-1.1.0/lib/thor/base.rb:485:in `start'
         8: from /home/ubuntu/.rvm/gems/ruby-2.7.4@ark/gems/thor-1.1.0/lib/thor/group.rb:232:in `dispatch'
         7: from /home/ubuntu/.rvm/gems/ruby-2.7.4@ark/gems/thor-1.1.0/lib/thor/invocation.rb:134:in `invoke_all'
         6: from /home/ubuntu/.rvm/gems/ruby-2.7.4@ark/gems/thor-1.1.0/lib/thor/invocation.rb:134:in `map'
         5: from /home/ubuntu/.rvm/gems/ruby-2.7.4@ark/gems/thor-1.1.0/lib/thor/invocation.rb:134:in `each'
         4: from /home/ubuntu/.rvm/gems/ruby-2.7.4@ark/gems/thor-1.1.0/lib/thor/invocation.rb:134:in `block in invoke_all'
         3: from /home/ubuntu/.rvm/gems/ruby-2.7.4@ark/gems/thor-1.1.0/lib/thor/invocation.rb:127:in `invoke_command'
         2: from /home/ubuntu/.rvm/gems/ruby-2.7.4@ark/gems/thor-1.1.0/lib/thor/command.rb:27:in `run'
         1: from /home/ubuntu/.rvm/gems/ruby-2.7.4@ark/gems/rails_admin-3.0.0.beta/lib/generators/rails_admin/install_generator.rb:26:in `install'
/home/ubuntu/.rvm/gems/ruby-2.7.4@ark/gems/rails_admin-3.0.0.beta/lib/generators/rails_admin/install_generator.rb:51:in `configure_for_webpacker5': uninitialized constant RailsAdmin::Version (NameError)

Reproduction steps

• Have rails_admin installed in version 2.0.2 ( gem 'rails_admin', '~> 2.0.2' in Gemfile).
• Change rails_admin to version 3.0.0.beta.
• Run bundle update rails_admin.
• Run bundle exec rails g rails_admin:install

Expected behavior
I expect to have a rails_admin.rb initializer with the updated values for 3.0.0.beta.

Additional context

• rails version: 6.0.4.4
• rails_admin version: 3.0.0.beta
• full stack trace (if there's an exception)

Add any other context about the problem here.

[estebanz01]

After manually editing lib/generators/rails_admin/install_generator.rb to not use the rails_admin version constant, yarn ask me to select 3.0.0.beta or 3.0.0.alpha so I'm not sure if the gem really needs to depend on that.

[mshibuya]

Thanks for reporting, just pushed the fix. Could you try with the master branch?

gem 'rails_admin', github: 'railsadminteam/rails_admin'

[estebanz01]

working as expected 😀