If we could lay our hand on an old version of the Jocly engine, from the time when it did support external game definitions, and install that here in addition to the newer Jocly, we could link to that.
I have version 0.1.0 installed in /play/jocly/, and I have version 0.0.1 in /play/jocly-master/. I think I thought I was putting a newer version there, but apparently I wasn't. I have found 0.9.12 on github. There are also 23 forks of Jocly. So, maybe someone is still working on it even though its creators have abandoned it.
I have version 0.1.0 installed in /play/jocly/, and I have version 0.0.1 in /play/jocly-master/. I think I thought I was putting a newer version there, but apparently I wasn't. I have found 0.9.12 on github. There are also 23 forks of Jocly. So, maybe someone is still working on it even though its creators have abandoned it.