Only numbers are missing Weasyprint PDF

I was able to fix this problem by eliminating the font "Segoe UI Emoji" from a font-family CSS declaration. Numbers started appearing again once this font was removed from CSS.

The bug seems to have started with some change on macOS 10.14.4.

The same issue occurs on Sierra (10.12) and High Sierra (10.13), as well as Mojave (10.14), especially when using Bootstrap 4.

The default body definition looks as follows:

  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol";

Where both Apple Color Emoji as well as Segoe UI Emojii can cause the final PDF to not display numbers properly.

Removing all mentions of the Emojii fonts brings the numbers back.

Note: The numbers are still there, you can copy and paste them, however, they are not actually visible.