Hi,
I had some trouble getting fonts to work for weasyprint in a Docker image I made with Nix via dockerTools.buildImage. This apparently not a very common use case, so here’s my workaround which fixed it for me. Maybe it helps someone.
Just adding pkgs.liberation_ttf isn’t enough. Setting FONTCONFIG_FILE=... doesn’t make it find the font, and fc-list shows only the one fallback font.
After some searching, it turns out the fonts end up in the Docker container under /share/fonts/..., while fontconfig searches for them in /usr/share/fonts/.... I couldn’t figure out how to teach dockerTools.buildImage to put the fonts in the right location, so I now execute this on startup:
ln -s /share /usr
(do include pkgs.coreutils so ln is available)
Nothing else is needed, fc-list now shows all the fonts, and weasyprint also finds them all, and I can make pretty PDFs again.