I've used nightly builds from the repo for the last two years or so, updating the packages maybe once a week. It's for this reason difficult to say exactly which version I was using just before I encountered the problem.

I publish the models on GitHub so they can definitely be had. Just need to push some changes...seems like it was half a year since I updated the repo.

I'm not sure exactly which build caused the problem, but after software updater did its thing sometime last week my models run with a tiny step-size in both DASSL and IDA whereas they have been just fine before. They are quite big models, but usually solve in 3-6 seconds. Now it takes over an hour to simulate the same.

I'm on Lubuntu 16.04.  I tried downgrading to the stable release, but it wouldn't start -- I assume the downgrade went awry.

I have done no changes to the model code.

Anyone know what might have caused this?

Should I make a ticket?