All extensions disabled due to expiration of intermediate signing cert

My extensions are also still running. Comments on the bugzilla bug restricted so adding details here and figuring that if this is useful someone can forward it to the right people

    $ date
    Fri May  3 22:45:22 EDT 2019

    $ date --utc
    Sat May  4 02:41:47 UTC 2019

    $ firefox --version # Installed from arch repositories
    Mozilla Firefox 66.0.3

about:config

    xpi.signatures.required true
    app.update.lastUpdateTime.xpi-signature-verification 1556920447
    extension.update.enabled true

1556920447 is unix timestamp Fri May 3 21:54:07 UTC 2019.

Edit: I think I know why. It checks the signatures daily, and the timing works out so it hasn't checked since the cert expired for me. Just luck, it will break within the next 21 hours for everyone. From the source code:

    const XPI_SIGNATURE_CHECK_PERIOD      = 24 * 60 * 60;

    [...]

    timerManager.registerTimer("xpi-signature-verification", () => {
      XPIDatabase.verifySignatures();
    }, XPI_SIGNATURE_CHECK_PERIOD);

Copying a potential workaround here from my lobste.rs comment, not really tested obviously

If it hasn’t broken yet for you, I think (but I’m not very much not sure) setting that preference to 1556940100 should keep it working until 24 hours from now. And if you keep updating that value every 23 hours to the output of date '+%s' until it is fixed via a firefox update it should keep working forever.

I think you need to restart the browser as well after updating the preference for the above idea to work.