Save features for HugoJS?

I just spent an hour playing cryptozookeeper at textadventures.online, and it had autosave so I thought I was fine. But then I died, and it won’t support undo.

Also, if you type Save, or Load, it just hangs, and you have to reload, at which point the autosave brings you back to where you need to be. I actually thought this meant the game was saving at checkpoints for me, but it was not.

I’m using chrome with adblocker, on a pc.

Development tools says the error is ‘Uncaught TypeError: hugoui.filePrompt is not a function’

If I had to guess, I’d wager that the session ran out of memory. I noticed in my playthrough of Cryptozookeeper that there were parts where I was lucky to get five UNDOs and that was with the normal interpreter; I would think it’s likely that HugoJS doesn’t set aside as much memory, and I know from experience that Hugo games act a bit wonky when they run out of memory.

I don’t fully understand how the Hugo undo system works, but it looks like the undo limits are defined by a C constant. It would be good to make that a variable which can be passed in instead (as in Git).

Also, HugoJS is I think only using a quarter of the Undo size of Hugor, which probably makes a big difference.