Export is missing Unicode emoji characters
I created a diagram with some shapes and text, among which there's an Unicode emoji character. It renders fine in the Dia window. However, when exporting the diagram to PNG, the emoji is invisible, though all the rest is here.
See attached diagram file (made with Dia) and the export made by Dia:
I'm using this package for supporting Unicode emojis: https://packages.debian.org/buster/fonts-noto-color-emoji