Sometimes doesn't work if privacy.resistFingerprinting is set to true, under unknown circumstances

[ghost]

This is an issue with Firefox and not with this package, but the whole thing doesn't work at all if privacy.resistFingerprinting is set to true, but only for newer versions of Firefox. On 68 ESR and 78 ESR, it worked fine, but with Firefox 83 on Xubuntu 20.04.1, the font config doesn't apply, Deja Vu remains the default font, and even if you manually change the fonts to Bitstream Vera in Firefox settings, the emoji font is never loaded so they don't work.

Figured I'd point it out in case someone else ran into the same problem, this seems to be the culprit. It makes a lot of sense why privacy.resistFingerprinting would block this, but if there's some other setting that can be tweaked to allow this to work while keeping this setting enabled, I'm all ears. Fortunately, most emoji seem to already render properly and in color in newer versions of Firefox, so this is not a pressing issue, but some of the newer emojis from Emoji 13.0 won't work. Mozilla might add those themselves in a future version of Firefox though which would mitigate this problem.

[ghost]

May be a (X)ubuntu-specific issue, and might not be limited to only newer versions of Firefox; on Linux Mint it seems to work fine. Might be something weird that Xubuntu does, but other distros don't?

[Schnark]

Didn't try, but according to https://bugzilla.mozilla.org/show_bug.cgi?id=1121643 the about:config property font.system.whitelist could be the tweak you're looking for.

[ghost]

Unfortunately this doesn't seem to help. The property does not exist, and creating it as an empty string doesn't fix it. So it must be something else.