I'm also curious if we should remove fontconfig-ultimate.

Oop, I should document this.

I'm not too familiar with fonts in Linux, but I suspect we want either fontconfig-penultimate or fontconfig-ultimate enabled to get things working correctly. Some feedback from @ttuegel or anyone else who knows how fonts are supposed to work would be helpful. My understanding is that fontconfig-penultimate is probably a good thing to have, it's just gotten out of date in the few years since its last release. This is a little bit too close to a release for my liking, but I suppose we can always revert it in the release-19.09 branch if it causes issues.

I'm not too familiar with fonts in Linux, but I suspect we want either fontconfig-penultimate or fontconfig-ultimate enabled to get things working correctly. Some feedback from @ttuegel or anyone else who knows how fonts are supposed to work would be helpful. My understanding is that fontconfig-penultimate is probably a good thing to have, it's just gotten out of date in the few years since its last release. This is a little bit too close to a release for my liking, but I suppose we can always revert it in the release-19.09 branch if it causes issues.

Sure, I totally understand if it's cutting it close. My issue currently with penultimate is that it appears to be out of date, causing issues in Gnome3, and it's a default configuration that has to be maintained outside of nixpkgs.

It would be helpful if someone who's familiar with the current state of fontconfig offered some insights.

Cc @volth as resident font guru.

I have been running with penultimate disabled for last week or so and did not encounter any issues. The current default is much worse for me as it lacks support for both emoji and math font classes.

I though we no longer patch freetype, as the main contention (ClearType hinting) was incorporated into upstream freetype when patents expired.

fontconfig-penultimate.nix offers exactly the same customization options as fontconfig.nix, so the only benefit that it could offer is assigning some font families to family classes. But lot of them have been added to upstream fontconfig in the meanwhile as well, in addition to a lot of new fonts that are not in penultimate (especially emoji). With this in mind, I am doubtful it is of any use at all.

If someone still wants it they can always enable it. But since vanilla fontconfig is perfectly usable, as evidenced by other distros running vanilla fontconfig, I say there is no place for penultimate to be enabled by default.

It seems we came to a good agreement during nixos office-hours, I'm going to merge as is.