On May 22nd, 2018 Jenkins tests for MobileFrontend started to fail with:
```
Scenario: Check components in diff summary
Given I am using the mobile site
And the page "Selenium diff test" exists and has at least "51" edits
And I am on the "Selenium diff test" page
When I click on the history link in the last modified bar
When I click the link in the header bar
Then the text of the first heading should be "Selenium diff test"
Message:
Uh-oh. Could not find link to Sauce Labs job URL.
Edit conflict. (editconflict) (MediawikiApi::ApiError)
/mnt/home/jenkins-deploy/.gem/2.1.0/gems/mediawiki_api-0.7.0/lib/mediawiki_api/client.rb:211:in `send_request'
/mnt/home/jenkins-deploy/.gem/2.1.0/gems/mediawiki_api-0.7.0/lib/mediawiki_api/client.rb:232:in `raw_action'
/mnt/home/jenkins-deploy/.gem/2.1.0/gems/mediawiki_api-0.7.0/lib/mediawiki_api/client.rb:36:in `action'
/mnt/home/jenkins-deploy/.gem/2.1.0/gems/mediawiki_api-0.7.0/lib/mediawiki_api/client.rb:111:in `edit'
/mnt/home/jenkins-deploy/.gem/2.1.0/gems/mediawiki_api-0.7.0/lib/mediawiki_api/client.rb:103:in `create_page'
/srv/jenkins-workspace/workspace/selenium-MobileFrontend/BROWSER/chrome/MEDIAWIKI_ENVIRONMENT/beta/PLATFORM/Linux/label/BrowserTests/tests/browser/features/step_definitions/create_page_api_steps.rb:12:in `block (3 levels) in <top (required)>'
/srv/jenkins-workspace/workspace/selenium-MobileFrontend/BROWSER/chrome/MEDIAWIKI_ENVIRONMENT/beta/PLATFORM/Linux/label/BrowserTests/tests/browser/features/step_definitions/create_page_api_steps.rb:11:in `upto'
/srv/jenkins-workspace/workspace/selenium-MobileFrontend/BROWSER/chrome/MEDIAWIKI_ENVIRONMENT/beta/PLATFORM/Linux/label/BrowserTests/tests/browser/features/step_definitions/create_page_api_steps.rb:11:in `block (2 levels) in <top (required)>'
/mnt/home/jenkins-deploy/.gem/2.1.0/gems/mediawiki_selenium-1.7.3/lib/mediawiki_selenium/page_factory.rb:43:in `block in on_page'
/mnt/home/jenkins-deploy/.gem/2.1.0/gems/page-object-1.1.0/lib/page-object/page_factory.rb:75:in `call'
/mnt/home/jenkins-deploy/.gem/2.1.0/gems/page-object-1.1.0/lib/page-object/page_factory.rb:75:in `on_page'
/mnt/home/jenkins-deploy/.gem/2.1.0/gems/mediawiki_selenium-1.7.3/lib/mediawiki_selenium/page_factory.rb:28:in `on_page'
/srv/jenkins-workspace/workspace/selenium-MobileFrontend/BROWSER/chrome/MEDIAWIKI_ENVIRONMENT/beta/PLATFORM/Linux/label/BrowserTests/tests/browser/features/step_definitions/create_page_api_steps.rb:10:in `block in <top (required)>'
/mnt/home/jenkins-deploy/.gem/2.1.0/gems/cucumber-1.3.20/lib/cucumber/core_ext/instance_exec.rb:48:in `instance_exec'
/mnt/home/jenkins-deploy/.gem/2.1.0/gems/cucumber-1.3.20/lib/cucumber/core_ext/instance_exec.rb:48:in `block in cucumber_instance_exec'
/mnt/home/jenkins-deploy/.gem/2.1.0/gems/cucumber-1.3.20/lib/cucumber/core_ext/instance_exec.rb:69:in `cucumber_run_with_backtrace_filtering'
/mnt/home/jenkins-deploy/.gem/2.1.0/gems/cucumber-1.3.20/lib/cucumber/core_ext/instance_exec.rb:36:in `cucumber_instance_exec'
/mnt/home/jenkins-deploy/.gem/2.1.0/gems/cucumber-1.3.20/lib/cucumber/rb_support/rb_step_definition.rb:97:in `invoke'
/mnt/home/jenkins-deploy/.gem/2.1.0/gems/cucumber-1.3.20/lib/cucumber/step_match.rb:25:in `invoke'
/mnt/home/jenkins-deploy/.gem/2.1.0/gems/cucumber-1.3.20/lib/cucumber/ast/step_invocation.rb:60:in `invoke'
/mnt/home/jenkins-deploy/.gem/2.1.0/gems/cucumber-1.3.20/lib/cucumber/ast/step_invocation.rb:38:in `accept'
/mnt/home/jenkins-deploy/.gem/2.1.0/gems/cucumber-1.3.20/lib/cucumber/ast/tree_walker.rb:106:in `block in visit_step'
/mnt/home/jenkins-deploy/.gem/2.1.0/gems/cucumber-1.3.20/lib/cucumber/ast/tree_walker.rb:170:in `broadcast'
/mnt/home/jenkins-deploy/.gem/2.1.0/gems/cucumber-1.3.20/lib/cucumber/ast/tree_walker.rb:105:in `visit_step'
/mnt/home/jenkins-deploy/.gem/2.1.0/gems/cucumber-1.3.20/lib/cucumber/ast/step_collection.rb:19:in `block in accept'
/mnt/home/jenkins-deploy/.gem/2.1.0/gems/cucumber-1.3.20/lib/cucumber/ast/step_collection.rb:18:in `each'
/mnt/home/jenkins-deploy/.gem/2.1.0/gems/cucumber-1.3.20/lib/cucumber/ast/step_collection.rb:18:in `accept'
/mnt/home/jenkins-deploy/.gem/2.1.0/gems/cucumber-1.3.20/lib/cucumber/ast/tree_walker.rb:100:in `block in visit_steps'
/mnt/home/jenkins-deploy/.gem/2.1.0/gems/cucumber-1.3.20/lib/cucumber/ast/tree_walker.rb:170:in `broadcast'
/mnt/home/jenkins-deploy/.gem/2.1.0/gems/cucumber-1.3.20/lib/cucumber/ast/tree_walker.rb:99:in `visit_steps'
/mnt/home/jenkins-deploy/.gem/2.1.0/gems/cucumber-1.3.20/lib/cucumber/ast/background.rb:44:in `block in accept'
/mnt/home/jenkins-deploy/.gem/2.1.0/gems/cucumber-1.3.20/lib/cucumber/ast/background.rb:54:in `block in with_visitor'
/mnt/home/jenkins-deploy/.gem/2.1.0/gems/cucumber-1.3.20/lib/cucumber/ast/scenario.rb:79:in `with_visitor'
/mnt/home/jenkins-deploy/.gem/2.1.0/gems/cucumber-1.3.20/lib/cucumber/ast/background.rb:53:in `with_visitor'
/mnt/home/jenkins-deploy/.gem/2.1.0/gems/cucumber-1.3.20/lib/cucumber/ast/background.rb:41:in `accept'
/mnt/home/jenkins-deploy/.gem/2.1.0/gems/cucumber-1.3.20/lib/cucumber/ast/tree_walker.rb:64:in `block in visit_background'
/mnt/home/jenkins-deploy/.gem/2.1.0/gems/cucumber-1.3.20/lib/cucumber/ast/tree_walker.rb:170:in `broadcast'
/mnt/home/jenkins-deploy/.gem/2.1.0/gems/cucumber-1.3.20/lib/cucumber/ast/tree_walker.rb:63:in `visit_background'
/mnt/home/jenkins-deploy/.gem/2.1.0/gems/cucumber-1.3.20/lib/cucumber/ast/feature.rb:36:in `accept'
/mnt/home/jenkins-deploy/.gem/2.1.0/gems/cucumber-1.3.20/lib/cucumber/ast/tree_walker.rb:27:in `block in visit_feature'
/mnt/home/jenkins-deploy/.gem/2.1.0/gems/cucumber-1.3.20/lib/cucumber/ast/tree_walker.rb:170:in `broadcast'
/mnt/home/jenkins-deploy/.gem/2.1.0/gems/cucumber-1.3.20/lib/cucumber/ast/tree_walker.rb:26:in `visit_feature'
/mnt/home/jenkins-deploy/.gem/2.1.0/gems/cucumber-1.3.20/lib/cucumber/ast/features.rb:28:in `block in accept'
/mnt/home/jenkins-deploy/.gem/2.1.0/gems/cucumber-1.3.20/lib/cucumber/ast/features.rb:17:in `each'
/mnt/home/jenkins-deploy/.gem/2.1.0/gems/cucumber-1.3.20/lib/cucumber/ast/features.rb:17:in `each'
/mnt/home/jenkins-deploy/.gem/2.1.0/gems/cucumber-1.3.20/lib/cucumber/ast/features.rb:27:in `accept'
/mnt/home/jenkins-deploy/.gem/2.1.0/gems/cucumber-1.3.20/lib/cucumber/ast/tree_walker.rb:21:in `block in visit_features'
/mnt/home/jenkins-deploy/.gem/2.1.0/gems/cucumber-1.3.20/lib/cucumber/ast/tree_walker.rb:170:in `broadcast'
/mnt/home/jenkins-deploy/.gem/2.1.0/gems/cucumber-1.3.20/lib/cucumber/ast/tree_walker.rb:20:in `visit_features'
/mnt/home/jenkins-deploy/.gem/2.1.0/gems/cucumber-1.3.20/lib/cucumber/runtime.rb:49:in `run!'
/mnt/home/jenkins-deploy/.gem/2.1.0/gems/cucumber-1.3.20/lib/cucumber/cli/main.rb:47:in `execute!'
/mnt/home/jenkins-deploy/.gem/2.1.0/gems/cucumber-1.3.20/bin/cucumber:13:in `<top (required)>'
/mnt/home/jenkins-deploy/.gem/2.1.0/bin/cucumber:23:in `load'
/mnt/home/jenkins-deploy/.gem/2.1.0/bin/cucumber:23:in `<main>'
tests/browser/features/special_history.feature:6:in `And the page "Selenium diff test" exists and has at least "51" edits'
```
It's not consistent, sometimes Chrome tests fail, sometimes Firefox, sometimes both.