# Fontconfig 2.18.1 issues
**URL:** https://discourse.nixos.org/t/fontconfig-2-18-1-issues/79057
**Category:** Uncategorized
**Created:** [July 19, 2026, 8:44pm UTC](https://discourse.nixos.org/t/fontconfig-2-18-1-issues/79057 "2026-07-19T20:44:45Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@zyx](https://discourse.nixos.org/u/zyx)
#### Post date: [July 19, 2026, 8:44pm UTC](https://discourse.nixos.org/t/fontconfig-2-18-1-issues/79057/1 "2026-07-19T20:44:45Z")
I notice on the web there are two distinct issues affecting Fontconfig 2.18.1 (in nixpkgs-unstable since around July 9). Just a heads up if you are also affected.
The first issue is your default generic family (e.g. sans, sans-serif, monospace) may not be correctly applied in your application (e.g. Chrome), due to a change in the font matching algorithm. This issue has been reported by both [NixOS](https://github.com/NixOS/nixpkgs/issues/541553) and [Arch](https://old.reddit.com/r/archlinux/comments/1twdfq4/fontconfig_2181_broke_generic_font_aliases/) users and to the [upstream](https://gitlab.freedesktop.org/fontconfig/fontconfig/-/work_items/532). A potential [fix](https://gitlab.freedesktop.org/fontconfig/fontconfig/-/merge_requests/535) will appear in Fontconfig 2.18.2.
The second issue is that some apps (e.g. [Ghostty](https://github.com/ghostty-org/ghostty/discussions/12931)) may have issues finding fonts or even crash ([1](https://gitlab.freedesktop.org/fontconfig/fontconfig/-/work_items/537), [2](https://gitlab.freedesktop.org/fontconfig/fontconfig/-/work_items/538)) when Fontconfig 2.18.1 reads an old cache. Again a potential [fix](https://gitlab.freedesktop.org/fontconfig/fontconfig/-/merge_requests/543) will appear in Fontconfig 2.18.2.
If this [Fontconfig update PR](https://github.com/NixOS/nixpkgs/pull/540695) gets merged before [the current staging-next cycle](https://github.com/NixOS/nixpkgs/pull/541843) ends, the bugs should be fixed once the latter PR [hits](https://nixpk.gs/pr-tracker.html?pr=541843) nixpkgs-unstable. Otherwise we will have to wait for another month for the next staging-next cycle.
Normally I would just advocate for PRs be merged using [this Discourse discussion thread](https://discourse.nixos.org/t/prs-ready-for-review/3032), but somehow I have used up my three chances to reply to that thread, and I cannot reply to that thread anymore as my Discourse account is considered new (despite being 13-month-old already).
---
### Author:  [@vcunat](https://discourse.nixos.org/u/vcunat)
#### Post date: [July 20, 2026, 5:06am UTC](https://discourse.nixos.org/t/fontconfig-2-18-1-issues/79057/2 "2026-07-20T05:06:44Z")
> [@zyx](#):
>
> If this [Fontconfig update PR](https://github.com/NixOS/nixpkgs/pull/540695) gets merged before [the current staging-next cycle](https://github.com/NixOS/nixpkgs/pull/541843) ends, the bugs should be fixed once the latter PR [hits](https://nixpk.gs/pr-tracker.html?pr=541843) nixpkgs-unstable.
That’s not how the workflow works. I merged it now, but that doesn’t get it into the current cycle (and it’s about a week too late for that rebuild-wise). So you could expect it to hit unstable in 2-3 weeks.
---
### Author:  [@zyx](https://discourse.nixos.org/u/zyx)
#### Post date: [July 20, 2026, 8:31am UTC](https://discourse.nixos.org/t/fontconfig-2-18-1-issues/79057/3 "2026-07-20T08:31:57Z")
Thanks for merging the PR and clarifying the workflow.