Normal interface text renders as monospace in Electron apps on KDE Wayland
Preflight Checklist
- I have read the Contributing Guidelines for this project.
- I agree to follow the Code of Conduct that this project adheres to.
- I have searched the issue tracker for a bug report that matches the one I want to file, without success.
Electron Version
40.10.2
What operating system(s) are you using?
Other Linux
Operating System Version
Aurora DX NVIDIA Open stable image 44.20260901.1, KDE Plasma 6.7.4 on Wayland, kernel 7.1.6-201.fc44.x86_64
What arch are you using?
x64
Last Known Working Electron version
No response
Does the issue also appear in Chromium / Google Chrome?
I don't know how to test
Expected Behavior
Normal interface text should render using the requested proportional UI font family, such as Noto Sans, while semantic code and terminal text remain monospaced.
Actual Behavior
In Hermes Desktop (Electron 40.10.2) and Grok Bot, normal interface text renders as a monospace font even though KDE and fontconfig resolve the requested UI families correctly.
Testcase Gist URL
No response
Additional Information
The behavior is reproducible on the currently booted aurora-dx-nvidia-open:stable image.
The same host-level Electron/Chromium font-matching behavior also affects unrelated Electron applications, while an embedded webfont bypasses it.
Changing the Hermes CSS stack to put system-ui first, with an explicit Noto Sans fallback, did not change the physical font. The reliable workaround was to bundle Noto Sans Regular/Medium/Bold as application webfonts under a private family name and put that family first. After rebuilding, proportional UI text rendered correctly while semantic code and terminal text remained monospaced.
Relevant font resolution output:
KDE general font: Noto Sans 10
fc-match system-ui: Noto Sans Regular
fc-match sans-serif: Noto Sans Regular
fc-match "Noto Sans": Noto Sans Regular
The issue was reproduced in Hermes Desktop and Grok Bot, and appears unlikely to be VS Code-specific. Package versions remain fontconfig-2.17.0-4.fc44, freetype-2.14.3-1.fc44, and harfbuzz-14.1.0-2.fc44.
Source: electron/electron