When editing an oVirt compute resource that's currently failing (e.g. bad admin password), the form won't load as it tries to get a list of quotas to display.

ActionView::Template::Error (401 Unauthorized):
    9:                  :class => "btn + #{datacenters.empty? ? "" : "btn-success"}",
    10:                  :'data-url' => test_connection_compute_resources_path) + image_tag('/assets/spinner.gif', :id => 'test_connection_indicator', :class => 'hide').html_safe }) %>
    11: <% quotas = (f.object.uuid.nil? && controller.action_name != 'test_connection') ? [] : f.object.quotas rescue []%>
    12: <%= select_f f, :ovirt_quota, quotas, :id, :name, {}, :label => _("Quota ID") %>
  app/helpers/layout_helper.rb:102:in `block in select_f'
  app/helpers/layout_helper.rb:130:in `block (2 levels) in field'
  app/helpers/layout_helper.rb:129:in `block in field'
  app/helpers/layout_helper.rb:124:in `field'
  app/helpers/layout_helper.rb:101:in `select_f'
  app/views/compute_resources/form/_ovirt.html.erb:12:in `_e7f9f939742f59e4e7d0512e1f936645'
  app/views/compute_resources/_form.html.erb:25:in `block in _d266af4e81ccfd6ac887a7d9ddb43142'
  app/helpers/layout_helper.rb:207:in `form_for'
  app/views/compute_resources/_form.html.erb:2:in `_d266af4e81ccfd6ac887a7d9ddb43142'
  app/views/compute_resources/edit.html.erb:3:in `_85d3215036b294085739cb8c859e0d6d'
  app/models/concerns/foreman/thread_session.rb:33:in `clear_thread'

It appears the f.object.quotas rescue [] doesn't work because the quotas are lazy-loaded, so it only fails when rendering the select box.