0:13.61 SUITE_START: web-platform-test - running 856 tests
 0:47.36 INFO Running testharness tests
 0:47.39 INFO Setting up ssl
 0:47.44 certutil Full command: /usr/bin/certutil -N -d /tmp/tmprYMnHs.mozrunner -f /tmp/tmprYMnHs.mozrunner/.crtdbpw
certutil 
 0:47.48 certutil 
 0:47.50 certutil 
Certificate Nickname                                         Trust Attributes
                                                             SSL,S/MIME,JAR/XPI

web-platform-tests                                           CT,, 

 0:47.52 INFO Application command: /home/test/build/firefox/firefox --marionette about:blank -profile /tmp/tmpogOO9n
 0:47.53 INFO Application command: /home/test/build/firefox/firefox --marionette about:blank -profile /tmp/tmprbo6jv
 0:47.54 INFO Starting runner
Failed to read: session.screen0.titlebar.left
Setting default value
Failed to read: session.screen0.titlebar.right
Setting default value
 0:49.75 pid:1275 Full command: /home/test/build/firefox/firefox --marionette about:blank -profile /tmp/tmpogOO9n
pid:1275 console.error: SearchCache: "_readCacheFile: Error reading cache file:" (new Error("", "(unknown module)"))
 0:51.05 pid:1275 1596676421960	Marionette	INFO	Listening on port 47423
 0:51.40 TEST_START: /WebCryptoAPI/derive_bits_keys/ecdh_bits.https.any.worker.html
 0:51.42 ERROR Traceback (most recent call last):
  File "/home/test/web-platform-tests/tools/wptrunner/wptrunner/testrunner.py", line 126, in run_test
    return self.executor.run_test(test)
  File "/home/test/web-platform-tests/tools/wptrunner/wptrunner/executors/base.py", line 285, in run_test
    self.on_environment_change(test.environment)
  File "/home/test/web-platform-tests/tools/wptrunner/wptrunner/executors/executormarionette.py", line 776, in on_environment_change
    self.protocol.testharness.load_runner(new_environment["protocol"])
  File "/home/test/web-platform-tests/tools/wptrunner/wptrunner/executors/executormarionette.py", line 140, in load_runner
    self._close_windows()
  File "/home/test/web-platform-tests/tools/wptrunner/wptrunner/executors/executormarionette.py", line 180, in _close_windows
    self.marionette.switch_to_window(runner_handle)
  File "/home/test/web-platform-tests/_venv2/lib/python2.7/site-packages/marionette_driver/marionette.py", line 1360, in switch_to_window
    self._send_message("WebDriver:SwitchToWindow", {"handle": handle, "focus": focus})
  File "/home/test/web-platform-tests/_venv2/lib/python2.7/site-packages/marionette_driver/decorators.py", line 26, in _
    return func(*args, **kwargs)
  File "/home/test/web-platform-tests/_venv2/lib/python2.7/site-packages/marionette_driver/marionette.py", line 602, in _send_message
    self._handle_error(err)
  File "/home/test/web-platform-tests/_venv2/lib/python2.7/site-packages/marionette_driver/marionette.py", line 622, in _handle_error
    raise errors.lookup(error)(message, stacktrace=stacktrace)
NoSuchWindowException: Unable to locate window: undefined
stacktrace:
	WebDriverError@chrome://marionette/content/error.js:175:5
	NoSuchWindowError@chrome://marionette/content/error.js:409:5
	GeckoDriver.prototype.switchToWindow@chrome://marionette/content/driver.js:1602:11
	despatch@chrome://marionette/content/server.js:305:40
	execute@chrome://marionette/content/server.js:275:16
	onPacket/<@chrome://marionette/content/server.js:248:20
	onPacket@chrome://marionette/content/server.js:249:9
	_onJSONObjectReady/<@chrome://marionette/content/transport.js:501:20