Building Output Fonts fails on current FontForge from Ubuntu repositories

[Jachimo]

Summary

FontForge errors and crashes when attempting to build the output fonts per the README file.

Steps to Reproduce

1. Clone repository (latest commit when I checked it out was 8034c0ad5)
2. cd GortonDigital
3. Execute fontforge generateStrokes.ff gortondigital.sfd

Expected Result

Fonts should be built using FontForge and the included source files.

Actual Result

FontForge throws an error, nothing is built:

➜  GortonDigital git:(master) fontforge generateStrokes.ff gortondigital.sfd
Copyright (c) 2000-2022. See AUTHORS for Contributors.
 License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
 with many parts BSD <http://fontforge.org/license.html>. Please read LICENSE.
 Version: 20201107
 Based on sources from 2022-01-13 19:13 UTC-ML-D-GDK3.
PythonUI_Init()
copyUIMethodsToBaseTable()
Internal Error (overlap): The end of the monotonic does not match that of the containing spline.
Internal Error (overlap): The end of the monotonic does not match that of the containing spline.
Internal Error (overlap): The end of the monotonic does not match that of the containing spline.
Internal Error (overlap): The end of the monotonic does not match that of the containing spline.
Internal Error (overlap): The end of the monotonic does not match that of the containing spline.
Internal Error (overlap): The end of the monotonic does not match that of the containing spline.
Internal Error (overlap): The end of the monotonic does not match that of the containing spline.
Internal Error (overlap): The end of the monotonic does not match that of the containing spline.
Internal Error (overlap): The end of the monotonic does not match that of the containing spline.
Internal Error (overlap): The end of the monotonic does not match that of the containing spline.
Internal Error (overlap): The end of the monotonic does not match that of the containing spline.
Internal Error (overlap): The end of the monotonic does not match that of the containing spline.
Internal Error (overlap): The end of the monotonic does not match that of the containing spline.
Internal Error (overlap): The end of the monotonic does not match that of the containing spline.
Internal Error (overlap): The end of the monotonic does not match that of the containing spline.
Internal Error (overlap): The end of the monotonic does not match that of the containing spline.
Internal Error (overlap): The end of the monotonic does not match that of the containing spline.
Internal Error (overlap): The end of the monotonic does not match that of the containing spline.
Internal Error (overlap): The end of the monotonic does not match that of the containing spline.
fontforge: ./fontforge/splinestroke.c:1701: RoundJoin: Assertion `intersects' failed.
[1]    1046360 IOT instruction (core dumped)  fontforge generateStrokes.ff gortondigital.sfd

Environment Info

• PopOS based on Ubuntu 22.04, kernel 6.2.6 generic on x86_64
• FontForge 20201107 (build date 2022-01-13 19:13 UTC), installed from Ubuntu repos (APT package version 1:20201107~dfsg-4build1)

[geneb]

Is there a known version of FontForge where this will not error out?

[jason-oliveira]

Still broken as of fontforge-20230101 in Ubuntu Oracular

[prohtex]

Same