Strange Font Rendering Issues

Help
1

I’m running a Wayland-only Plasma setup on Nixpkgs unstable, and all has been working well for the past few months, until suddenly I started getting really strange font rendering issues on electron-based applications. Here’s a good view of the type of thing I’m seeing (notice the uneven rendering on the “TIMELINE” and “OUTLINE” accordions):

image
image367×140 24.8 KB

My font config adds font packages, but doesn’t attempt to force any settings. I do use NIXOS_OZONE_WL = "1" and ELECTRON_OZONE_PLATFORM_HINT = "wayland"; to force wayland on all Chrome and Electron instances. My Plasma config does use hidpi scaling on some diplays, but I get the same results on all displays, regardless of hidpi. Changing the anti-aliasing settings in the Plasma config doesn’t seem to have any effect one way or another on this particular issue.

Any ideas on what I might try to resolve this?

2

Same problem here running Hyprland on NixOS. I also tried a bunch of different things like changing fonts and settings. My monitor is 4k 60hz from lg. This problem only occurs in PHP storm and nowhere else. If I terminal besides it with the same font it works just fine.

2025-10-08T12:21:34,722472334+02:00

3

I have similar problems in VS Code.
In my case, it was due to my Nvidia card. There were no font rendering issues on AMD or Intel.

4

perchance it could be…

fonts.fontconfig.antialias = false; # default = true

Enable font antialiasing. At high resolution (> 200 DPI), antialiasing has no visible effect; users of such displays may want to disable this option.

but you should also check out these little guys:

fonts.fontconfig.cache32Bit = true; # default = false

…

fonts.fontconfig.allowBitmaps

fonts.fontconfig.hinting.*

fonts.fontconfig.subpixel.*

EDIT: oh… you are using wayland, nevermind! i cant read, again! :sweat_smile:

5

I fixed it with changing my monitor scale back to 1,

From:

monitor = DP-1, 3800x2160@60, 0x1080,  1,5

To:

monitor = DP-1, 3800x2160@60, 0x1080, 1

This fixed the issue for me. And since i used it for a day i think scale 1 is better too.

6

This is a bug in the vscode. See Enable FontationsLinuxSystemFonts feature · Issue #261605 · microsoft/vscode · GitHub
patch it:

pkgs.vscode.overrideAttrs ({
      postPatch = ''
        substituteInPlace resources/app/out/main.js \
          --replace 'CalculateNativeWinOcclusion,FontationsLinuxSystemFonts,''${Ne.commandLine.getSwitchValue("disable-features")}' \
          'CalculateNativeWinOcclusion,''${Ne.commandLine.getSwitchValue("disable-features")}'
      '';
    })
7

Wow, that’s brilliant. Thanks so much!

8

BTW, that worked one time and then stopped working. This simpler/broader patch is working at the moment:

vscode = pkgs.vscode.overrideAttrs ({
  postPatch = ''
    substituteInPlace resources/app/out/main.js \
      --replace 'FontationsLinuxSystemFonts,' '''
  '';
});