emacs -Q -l bug.el, and then C-x 8 RET.

> Does this happen with any font you use as the default font?


I tested against some fonts with

    emacs -Q --eval "(set-face-attribute 'default nil :family FONT)" -l bug.el

Indeed the choice of the default font seems relevant. The observed results:

| Menlo (default monospace font) | crash    |
| Courier New                    | crash    |
| Courier Prime                  | no crash |
| JetBrains Mono                 | no crash |
| Cascadia Mono                  | crash    |
| Fira Code                      | no crash |
| Fira Mono                      | crash    |

Hope this helps.