Vendorized FontAwesome is unreadable with Sprockets 4

[bodrovis]

After upgrading to Sprockets 4, admin page stops working at all:

Error: File to import not found or unreadable: rails_admin/font-awesome.
        on line 60:1 of F:/Ruby25/lib/ruby/gems/2.5.0/gems/rails_admin-2.0.0/app/assets/stylesheets/rails_admin/rails_admin.scss.erb
>> @import 'rails_admin/font-awesome';

Commenting out the specified line fixes the issue. This happens on Rails 6 on Windows and Mac.

Here is a sample fresh app demonstrating the problem: https://github.com/bodrovis/RailsAdminSprockets To reproduce:

1. Clone the repo
2. Install gems
3. Run server
4. Visit http://localhost:3000/admin
5. Observe the error

[bodrovis]

Here's the proposed fix cselmer@3fe3783 but I can't send PR atm because the test suite is not working for me (even before I start changing anything). I keep seeing CanCan is undefined at ./spec/integration/authorization/cancancan_spec.rb:5:in class:Ability' `

[gaganawhad]

@mshibuya Thanks for your work on maintaining rails_admin!

Thoughts on this issue? We are experiencing this as well, and I would expect a lot of others too given that Sprockets 4 was released recently, except that I am not seeing that much activity on this issue. Let us know if the two of us are missing something.

Looks like cselmer@3fe3783 commit, which @bodrovis linked above, should be the fix.

@bodrovis Thanks for creating this issue!

[bodrovis]

@gaganawhad Hello! Please check my PR, I've fixed this issue (with Chris' help) and other failing tests #3207