Analyzing crash data of Firefox

If Firefox crashes whilst under automation, it’s helpful to retrieve the generated crash data aka minidump files, and report these to us.

Retrieve the crash data

Because geckodriver creates a temporary user profile for Firefox, it also automatically removes all its folders once the tests have been finished. That also means that if Firefox crashed the created minidump files are lost. To prevent that a custom profile has to be used instead. The following code shows an example by using the Python Selenium bindings on Mac OS:

import tempfile

from selenium import webdriver
from selenium.webdriver.firefox.options import Options

# Custom profile folder to keep the minidump files
profile = tempfile.mkdtemp(".selenium")
print("*** Using profile: {}".format(profile))

# Use the above folder as custom profile
opts = Options()
opts.add_argument("-profile")
opts.add_argument(profile)
opts.binary = "/Applications/Firefox.app/Contents/MacOS/firefox"

driver = webdriver.Firefox(
    options=opts,
    # hard-code the Marionette port so geckodriver can connect
    service_args=["--marionette-port", "2828"]
)

# Your test code which crashes Firefox

Executing the test with Selenium now, which triggers the crash of Firefox will leave all the files from the user profile around in the above path.

To retrieve the minidump files navigate to that folder and look for a sub folder with the name minidumps. It should contain at least one series of files. One file with the .dmp extension and another one with .extra. Both of those files are needed. If more crash files are present grab them all.

Attach the files as best archived as zip file to the created geckodriver issue on Github.

Getting details of the crash

More advanced users can upload the generated minidump files themselves and receive details information about the crash. Therefore find the crash reporter folder and copy all the generated minidump files into the pending sub directory. Make sure that both the .dmp and .extra files are present.

Once done you can also view the crash reports.

If you submitted a crash please do not forget to also add the link of the crash report to the geckodriver issue.

Enabling the crash reporter

By default geckodriver disables the crash reporter so it doesn’t submit crash reports to Mozilla’s crash reporting system, and also doesn’t interfere with testing.

This behaviour can be overridden by using the command line argument --enable-crash-reporter. You can view the crash reports and share it with us after submission.

Important: Please only enable the crash reporter if the above mentioned solution does not work.