Some Font Awesome icons not usable

I use the following in a modular features page of the Quark theme:

        icon: 'fa fa-mastodon'
        header: '<a rel="me" href="https://mastodon.online/@Zeitgeistbeweging">Mastodon</a>'
        text: null
        url: null

Which in the admin panel looks like:

So it's able to do a successful lookup. My guess is that Font Awesome 4.7.0 (which is installed in Grav 1.7.3) doesn't have the Mastodon icon and that Grav does a lookup online, which probably uses Font Awesome 5.x.

I also read somewhere that Font Awesome 5 has breaking changes with Font Awesome 4 and that's why it's not updated yet in Grav. I guess Grav 2.0 will fix that?

I would like to confirm this, to ensure I'm not overlooking something. What would be a workaround? I'll use the Twitter logo in the meantime.

@AquaL1te,

As far as I know, Font-Awesome 4.7 does not contain fa-mastodon.

Admin uses a fork of Font-Awesome which seems to have added 'fa-mastodon'. So, no online lookup.

Workaround:

• Use the Twitter logo in the meantime. ;-)
• Or copy the fonts from 'user/plugins/admin/themes/grav/fonts/forkawesome*' to '/user/themes/quark/fonts'.
  Haven't tried it myself...
• Or upgrade to Font-Awesome as explained in another post.