1. mkdir px/a/ 2. While holding alt, firefox -profile ~/px/a/ Result: JavaScript error: chrome://browser/content/safeMode.js, line 80: resetSupported is not defined Probably a regression from https://hg.mozilla.org/mozilla-central/rev/37015ff213ae safeMode.js might just need a - resetSupported() + ResetProfile.resetSupported()

Thanks. https://hg.mozilla.org/integration/mozilla-inbound/rev/135d3870f654

I tried to verify this fix, but I don't get the same error as the one mentioned in the Description (when following the steps from the Description). Just to be sure I got it right, is the px directory created in the profiles directory? Could you please give me some more details?

I'm just creating ~/px/ and ~/px/a/ in order to use ~/px/a/ as a fresh, disposable Firefox profile. [-P name] would use a subdirectory of the profiles directory, but [-profile dir] uses just the specified directory.

If you don't hold Alt, you should see files like places.sqlite appear in the profile directory. If you do hold Alt (might be Shift instead on Windows?), you should see a Safe Mode dialog.