500 on MR page - ActionView::Template::Error: No route matches

Stating Testing gitlab-org/release/tasks#131 (closed)

Found on https://staging.gitlab.com/gitlab-org/gitlab-ce/merge_requests/12841

Sentry Error: https://sentry.gitlap.com/gitlab/staginggitlabcom/issues/143029/

ActionController::UrlGenerationError: No route matches {:action=>"show", :controller=>"projects/commit", :id=>nil, :namespace_id=>#<Group id:9970 @gitlab-org>, :project_id=>#<Project id:13083 gitlab-org/gitlab-ce>} missing required keys: [:id]
  config/application.rb:211:in `block (4 levels) in <class:Application>'
    send(name, project&.namespace, project, *args) # rubocop:disable GitlabSecurity/PublicSend
  app/helpers/notes_helper.rb:92:in `discussion_path'
    project_commit_path(discussion.project, discussion.noteable, anchor: anchor)
  app/views/discussions/_discussion.html.haml:23:in `_app_views_discussions__discussion_html_haml___1801392728352659345_70348226539360'
    - url = discussion_path(discussion)
  app/views/shared/notes/_notes.html.haml:6:in `block in _app_views_shared_notes__notes_html_haml___2136718428236835631_70348294440500'
    = render 'discussions/discussion', discussion: discussion
  app/views/shared/notes/_notes.html.haml:2:in `each'
    - @discussions.each do |discussion|
...
(214 additional frame(s) were not displayed)

ActionView::Template::Error: No route matches {:action=>"show", :controller=>"projects/commit", :id=>nil, :namespace_id=>#<Group id:9970 @gitlab-org>, :project_id=>#<Project id:13083 gitlab-org/gitlab-ce>} missing required keys: [:id]