Gathering Debug Logs

Follow the instructions in this video or the written steps in both sections below.

Enable Debug Logging

1. Enter "about:config" in the URL bar.
2. You may see a warning screen cautioning you about changing advanced preferences. Click the button to ignore the warning.
3. Set extensions.formautofill.loglevel pref to Debug
4. Make sure all of the following prefs are set to 'true'. (Find a pref by entering its name in the "Filter" box at the top of the page. Toggle its value by either clicking the ⇌ (Toggle) icon or double-clicking the line.)

   devtools.browserconsole.contentMessages
   devtools.browserconsole.filter.error
   devtools.browserconsole.filter.warn
   devtools.browserconsole.filter.info
   devtools.browserconsole.filter.log
   devtools.browserconsole.filter.debug
   

5. Restart Firefox

View the Logging

1. To view the logging, open the Browser Console and/or Browser Content Toolbox (for logs related to in-page stuff) from the Tools → Web Developer menu. If you don't see these, follow the instructions on the MDN page to enable it.
   • Note that the above consoles are different than the Web Console that you use for regular web development.
2. Make sure the log level toggles ("Errors", "Warnings", "Logs", …, "Debug") are all enabled in the Browser Console. "CSS" should ideally be disabled.
3. Load the problematic web and reproduce the issue in in the browser. You might see messages in the Browser Console like:

FormAutofillContent: identifyAutofillFields: https://www.google.com
FormAutofillHandler: Creating new credit card section with flowId  

To copy/save the logs, right-click in an open area of the console and choose "Save all Messages to File" or choose "Copy all Messages" depending on which you prefer. Include them as an attachment on your bug report, not in the body of a comment.