ActionView::Template::Error: PG::UndefinedTable: ERROR: missing FROM-clause entry for table "iss...

https://sentry.gitlap.com/gitlab/gitlabcom/issues/4471/

PG::UndefinedTable: ERROR:  missing FROM-clause entry for table "issues"
LINE 1: ... 'ui') AND "labels"."project_id" = 13083 GROUP BY issues.id ...
                                                             ^

  app/views/projects/merge_requests/_merge_requests.html.haml:2:in `_app_views_projects_merge_requests__merge_requests_html_haml__3718577933208298417_74618820'
    = render @merge_requests
  app/views/projects/merge_requests/index.html.haml:20:in `_app_views_projects_merge_requests_index_html_haml__1464217200771759219_85299560'
    = render 'merge_requests'
  app/controllers/projects/merge_requests_controller.rb:44:in `index'
    respond_to do |format|
  lib/gitlab/metrics/rack_middleware.rb:17:in `block in call'
    retval = trans.run { @app.call(env) }
  lib/gitlab/metrics/transaction.rb:45:in `run'
    yield
...
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ActiveRecord::StatementInvalid: PG::UndefinedTable: ERROR:  missing FROM-clause entry for table "issues"
LINE 1: ... 'ui') AND "labels"."project_id" = 13083 GROUP BY issues.id ...
                                                             ^
: SELECT  "merge_requests".* FROM "merge_requests" INNER JOIN "label_links" ON "label_links"."target_id" = "merge_requests"."id" AND "label_links"."target_type" = $1 INNER JOIN "labels" ON "labels"."id" = "label_links"."label_id" WHERE "merge_requests"."deleted_at" IS NULL AND ("merge_requests"."state" IN ('opened','reopened')) AND "merge_requests"."target_project_id" = 13083 AND "merge_requests"."assignee_id" = $2 AND "labels"."title" IN ('relative_url_root', 'ui') AND "labels"."project_id" = 13083 GROUP BY issues.id HAVING count(distinct labels.title) = 2  ORDER BY "merge_requests"."id" DESC LIMIT 20 OFFSET 0
  app/views/projects/merge_requests/_merge_requests.html.haml:2:in `_app_views_projects_merge_requests__merge_requests_html_haml__3718577933208298417_74618820'
    = render @merge_requests
  app/views/projects/merge_requests/index.html.haml:20:in `_app_views_projects_merge_requests_index_html_haml__1464217200771759219_85299560'
    = render 'merge_requests'
  app/controllers/projects/merge_requests_controller.rb:44:in `index'
    respond_to do |format|
  lib/gitlab/metrics/rack_middleware.rb:17:in `block in call'
    retval = trans.run { @app.call(env) }
  lib/gitlab/metrics/transaction.rb:45:in `run'
    yield
...
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ActionView::Template::Error: PG::UndefinedTable: ERROR:  missing FROM-clause entry for table "issues"
LINE 1: ... 'ui') AND "labels"."project_id" = 13083 GROUP BY issues.id ...
                                                             ^
: SELECT  "merge_requests".* FROM "merge_requests" INNER JOIN "label_links" ON "label_links"."target_id" = "merge_requests"."id" AND "label_links"."target_type" = $1 INNER JOIN "labels" ON "labels"."id" = "label_links"."label_id" WHERE "merge_requests"."deleted_at" IS NULL AND ("merge_requests"."state" IN ('opened','reopened')) AND "merge_requests"."target_project_id" = 13083 AND "merge_requests"."assignee_id" = $2 AND "labels"."title" IN ('relative_url_root', 'ui') AND "labels"."project_id" = 13083 GROUP BY issues.id HAVING count(distinct labels.title) = 2  ORDER BY "merge_requests"."id" DESC LIMIT 20 OFFSET 0
  app/views/projects/merge_requests/_merge_requests.html.haml:2:in `_app_views_projects_merge_requests__merge_requests_html_haml__3718577933208298417_74618820'
    = render @merge_requests
  app/views/projects/merge_requests/index.html.haml:20:in `_app_views_projects_merge_requests_index_html_haml__1464217200771759219_85299560'
    = render 'merge_requests'
  app/controllers/projects/merge_requests_controller.rb:44:in `index'
    respond_to do |format|
  lib/gitlab/metrics/rack_middleware.rb:17:in `block in call'
    retval = trans.run { @app.call(env) }
  lib/gitlab/metrics/transaction.rb:45:in `run'
    yield
...
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That's because we're grouping by issues.id in Issuable.with_label where we should group by self.arel_table[:id]!