Arvados

Ran a local instance of workbench and confirmed that seems to be an issue with the themes_for_rails gem:

{"method":"GET","path":"/themes/curoverse/images/etc/passwd","format":"html","controller":"ThemesForRails::AssetsController","action":"images","status":500,"error":"SystemStackError: stack level too deep","duration":631.13,"view":0.0,"db":0.0,"request_id":null,"params":{"theme":"curoverse","asset":"etc/passwd"},"@timestamp":"2019-05-01T16:23:44.827Z","@version":"1","message":"[500] GET /themes/curoverse/images/etc/passwd (ThemesForRails::AssetsController#images)"}

SystemStackError (stack level too deep):
  vendor/cache/themes_for_rails-61154877047d/lib/themes_for_rails.rb:8:in `config'
  vendor/cache/themes_for_rails-61154877047d/lib/themes_for_rails/interpolation.rb:6:in `interpolate'
  vendor/cache/themes_for_rails-61154877047d/lib/themes_for_rails/common_methods.rb:63:in `theme_asset_path_for'
  vendor/cache/themes_for_rails-61154877047d/lib/themes_for_rails/assets_controller.rb:43:in `asset_path'
  vendor/cache/themes_for_rails-61154877047d/lib/themes_for_rails/assets_controller.rb:31:in `find_themed_asset'
  vendor/cache/themes_for_rails-61154877047d/lib/themes_for_rails/assets_controller.rb:36:in `find_themed_asset'
  vendor/cache/themes_for_rails-61154877047d/lib/themes_for_rails/assets_controller.rb:36:in `find_themed_asset'
  vendor/cache/themes_for_rails-61154877047d/lib/themes_for_rails/assets_controller.rb:36:in `find_themed_asset'
...

We're using a fork of the gem as the project was abandoned some years ago.

This may be needed to be done at the same time as #15176