Wikimedia Bugzilla is closed!

The VisualEditor headings.feature has begun to fail[1] when run via CloudBees (but not when run locally).  Relevant Selenium log message is (example is for the "Subheading1" scenario, but the pattern is the same for all scenarios in this test):

00:25:21.230 INFO - Executing: [find element: By.xpath: .//a[@title='^3']] at URL: /session/83a0781b-247c-4f0a-88f8-a93cef166a15/element)
00:25:21.247 WARN - Exception thrown
org.openqa.selenium.NoSuchElementException: Unable to locate element: {"method":"xpath","selector":".//a[@title='^3']"}
Command duration or timeout: 13 milliseconds
For documentation on this error, please visit: http://seleniumhq.org/exceptions/no_such_element.html
Build info: version: '2.39.0', revision: 'ff23eac', time: '2013-12-16 16:11:15'
System info: host: 'chef', ip: '127.0.1.1', os.name: 'Linux', os.arch: 'i386', os.version: '3.2.0-56-virtual', java.version: '1.6.0_31'
Session ID: 185a49ff-3267-43a3-ad44-3e6881cd0d43
Driver info: org.openqa.selenium.firefox.FirefoxDriver
Capabilities [{platform=LINUX, acceptSslCerts=true, javascriptEnabled=true, browserName=firefox, rotatable=false, locationContextEnabled=true, version=26.0, cssSelectorsEnabled=true, databaseEnabled=true, handlesAlerts=true, browserConnectionEnabled=true, nativeEvents=false, webStorageEnabled=true, applicationCacheEnabled=true, takesScreenshot=true}]

The problem does not repro when the test is run on a MacBook, and the insertion of the following command into the headings_steps.rb file at appropriate points succeeds as expected:

@browser.a(:xpath, ".//a[@title='^3']").should exist

Need to figure out why these test scenarios fail when run via CloudBees, since they seem to be perfectly legitimate test cases.

[1] https://wmf.ci.cloudbees.com/view/r-ve/job/VisualEditor-en.wikipedia.beta.wmflabs.org-linux-firefox/327/testReport/