How to pack fonts into AppImage for graphical application?

[xinyifly]

1. The bundled AppImage cannot use my fonts specified in configuration.nix, it shows square blocks for CJK characters.
2. The only font installation that worked is fonts under $HOME/.local/share/fonts

$ nix bundle --bundler github:ralismark/nix-appimage
$ ./my-app.AppImage
Fontconfig error: Cannot load default config file: No such file: (null)
qt.qpa.wayland: EGL not available