With the new extension signing requirements, ./test.sh --justrun is completely broken. HTTPS Everywhere is disabled when the browser starts up. I patched the skeleton profile's prefs.js, to disable the signing requirements, but that isn't actually sufficient to enable the extension - it just turns on the "Enable" button in about:addons. This is problematic since (at least on OS X - not sure why it's working without PR #2891 applied, though) restarting Firefox to enable an extension registers as closing the app, so test/firefox.sh moves on and nukes the profile directory.

I've been at this for about 3 hours now. No matter what I do, Firefox seems to disable the extension because it's a "foreign extension" (third-party install, essentially), as printed on stdout. I suspect that Mozilla tightened some logic with this at the same time they did the signature enforcement, and didn't bother to document it because they didn't realize it would break automated workflows.

The trick to enabling an extension seems to be setting the userDisabled JSON key in extensions.json to false, but no matter what I do, Firefox changes this to true on startup. I have no idea what's going on, and suspect that we'll have to reach out to Mozilla for help. Bugzilla, anyone?

Protip for anyone debugging this: instead of following the advice in test/firefox/README and doing diff -r, cd into your profile directory and initialize a Git repository.

See also #2051