Hotfix release

Those that follow the Github repositories closely are probably aware that we have to do a hotfix release due two separate issues. Thanks to @avehtari, @Stevo15025 and @bbbales2 for spotting and reporting them.

I am coordinating with @serban-nicusor to make this as painless as possible. We have three issues opened for the three repos if anyone has any questions/comments:

The plan is to do the Math 3.1.1 release tonight and then proceed with the rest tomorrow (me and Nic are in the CET timezone).


How about in the future tagging a release candidate, e.g., a week before and asking people to test? This is quite common in projects with users having diverse system configurations and usage patterns. I didn’t want to test before seeing the New Features list which was available only just before the release, but the problems were quite obvious in my use case.

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We have been doing the “feature freeze week” since 2.21. However, this time, there was no announcement or post on Discourse and that is where things went wrong. We have to do better next time. The same point was made by @syclik and I fully agree with both of you. Someone has to do a post formally stating that we are in a feature freeze and to request testing.

I guess the problem here was also that there was a transition of responsibilities for the release from @seantalts to @jonah and Jonah was away. So no one was officially running the release and the release was coordinated among the rest of developers. We should have maybe postponed the release for that reason.

I decided to jump in to help with the hotfix release even though I was not sanctioned by anyone with more seniority on the project. My thinking was that the longer we waited with the hotfix, the harder it will get. Hopefully, no one took that as a coup.


I do remember feature freeze week, but I don’t remember there being rc-tags. These would help instead of following all the discussion going on github of which commits to cherry pick and which not. “feature freeze week” announcement felt being directed for developers and not for eager users. rc-tags would make it easier to just try install and run.

That was brave thing to do! Thanks for making it happen


Great idea. @serban-nicusor we should note that somewhere for the next release.


Sounds good to me, thanks. And thanks to everyone who helped with the hotfix release!

Thanks for managing all this… cmdstan is tagged with 2.21.1, but I think the binaries which contain stan + stan-math are not yet build. I thought these would be created with the tagging, but looks like some scripts need to turn their wheels.

Nic tagged the release yesterday and he left the tests running so we double check everything is ready. He also didnt have the release notes. The plan is to make the official release + tarball today.