Arvados

After the bug in issue #3031, workbench tries to run the error page, which blows up like this:

Rendered application/error.html.erb within layouts/application (1.2ms)
Completed 500 Internal Server Error in 664ms

ActionView::Template::Error (ArvadosApiClient::NotLoggedInException):
173: <% end >
174: My projects
175: </li>
176: < my_project_tree.each do |pnode| >
177: < next if pnode[:object].class != Group >
178: <li style="padding-left: <= pnode[:depth]-1 >em">
179: <= link_to(pnode[:object].name, project_path(pnode[:object].uuid), data: {object_uuid: pnode[:object].uuid, name: 'name'}) %>
app/models/arvados_api_client.rb:88:in `api'
app/models/arvados_resource_list.rb:69:in `where'
app/models/arvados_resource_list.rb:75:in `results'
app/models/arvados_resource_list.rb:88:in `each'
app/controllers/application_controller.rb:613:in `build_project_trees'
app/controllers/application_controller.rb:600:in `my_project_tree'
app/views/layouts/application.html.erb:176:in `_app_views_layouts_application_html_erb___4156834235341399204_21093860'
app/controllers/application_controller.rb:46:in `block (2 levels) in render_error'
app/controllers/application_controller.rb:40:in `render_error'
app/controllers/application_controller.rb:58:in `render_exception'