Thanks for preparing a draft! Comments inline.
Quoting Jan Alexander Steffens (heftig) (2025-01-15 13:40:30)
> Apps using the incoming `pango 1.56.0` may fail to render text or crash if
> the user has also run apps based on Electron 29 or older.
>
> To immediately mitigate the issue, delete `~/.cache/fontconfig` or run
> `fc-cache`. However, further use of old Electron apps may cause the problem
This should be `fc-cache -f` (just `fc-cache` is insufficient).
> to reappear.
>
> We recommend
>
> - switching newer versions of the Electron applications that use at least
> Electron 30,
> - using Flatpak releases of the applications, or
> - giving the applications their own XDG cache directory by running them
> with `XDG_CACHE_HOME=${HOME}/.cache/appname` in the environment.
Suggestion: Consider replacing "appname" with "<appname>" or "$appname"
to clarify that those paths should be application-specific, not
literally "appname". (Even though, on second thought, a shared second
cache directory may actually work too, as long as only the right set of
applications is added to it.)
>
> ### Technical details
>
> Pango 1.56.0 depends on "font wrapper" information provided by Fontconfig
> 2.15.0 in order to determine whether it supports a font.
>
> Electron 29 and older are shipping a Git snapshot of Fontconfig that has
> the same cache version (`9`) as Fontconfig 2.15.0. but lacks the font
Typo: Remove period after Fontconfig version.
> wrapper information.
>
> The Electron version of Fontconfig fails to parse the cache files generated
> by our version of Fontconfig. It then regenerates them without the font
> wrapper information.
>
> Our Fontconfig still considers these cache files valid, but the missing
> font wrapper information leads to Pango failing to find any valid fonts.
>
> This issue is being tracked at [pango#1](
> https://gitlab.archlinux.org/archlinux/packaging/packages/pango/-/issues/1).
Thanks again!
