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.