Took me a minute to figure this out and thought I’d save others some time by posting this here. Not sure why but the repo is no longer available on github, causing the rebuild to fail. Maybe chronos is now in core? Removing that line and rebuilding works.
It’s in core for over a year now:
Yeah, I figured. But the chronos plugin repo has more recently been made unavailable, it seems. People like me with forums that have been around for a while seem to regularly run into trouble with this sort of thing. No biggie but a bit of a time waster.