Skip to content

Capture Firefox log and Mozilla bisection

Eberhard Beilharz edited this page Apr 22, 2026 · 2 revisions

This is just some brief instructions I was given when interacting with the Mozilla team. Far more in-depth info can be found in their documentation but I thought I would record the instructions I received as they were helpful.

Firefox to log keyboard event handling

  1. Open a testcase in a tab
  2. Open about:logging in another tab
  3. Choose "Logging to a file" radio button and type a path to save the log into the text field, then, press "Set Log File" button
  4. Set "New log modules:" field to timestamp,KeyboardHandler:4,IMEHandler:4,sync and click "Set Log Module" button.
  5. If you see "Start logging" button in top of the page, click it.
  6. Back to the tab loaded the testcase with mouse
  7. Click the editor and do the minimum steps to reproduce the bug
  8. Back to the tab loaded about:logging with mouse
  9. Click the "Stop logging" button
  10. The Log file is available the path set above.

See also Mozilla doc.

Bisect Firefox Builds

You bisect a regression point with mozregression? It doesn't user your profile directly unless you choose such option in the UI so that you can do it without dataloss.

Clone this wiki locally