Analyzing crash data of Firefox

It’s not uncommon that under some special platform configurations and while running automated tests via Selenium and geckodriver Firefox could crash. In those cases it is very helpful to retrieve the generated crash data aka minidump files, and report these to us.

Retrieve the crash information

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 or just a tab crashed the created minidump files cannot be retrieved. To prevent that the MINIDUMP_SAVE_PATH environment variable can be used. It needs to be forwarded to geckodriver and has to point to an existing folder on the local machine. Then, whenever a crash occurs the related crash information will then be written to the <uuid>.dmp and <uuid>.extra files within the given folder.

MINIDUMP_SAVE_PATH="/home/test/crashes" pytest path/to/

By running this command Firefox will now write minidump files to that folder:

$ ls /home/test/crashes

Note that both of those files are needed when you want to file an issue for geckodriver. If more 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.