I’m really glad to hear that the Makefile and the PDF have been helpful to you!
My apologies — you’re right, that error happens because I excluded the assets/images/emojis and assets/images/emojis_lite directories from version control.
I’ve just updated the repository to clarify the origin of the assets, and added a readme.txt file inside both assets/images/emojis and assets/images/emojis_lite.
Additionally, in assets/images/emojis/readme.txt you’ll find a short description of a Go script that renames duplicate images (based on file content), so they can be identified and optionally deleted.
Thanks again for your support! 🙌