Just thought I'd reinstall #OpenBSD 7.9 again and then switch to the latest snapshot to see if my not being able too boot /bsd past the 14th May snapshot and it now fails to verify the downloaded stuff 😂
Good thing I've still my trusty #FreeBSD laptop.

Even more random redoing the sysupgrade -s and it passes straight away and upgrades. Does it boot the /bsd ? No it does not only boot.rd and boot.sp boot.
@justine Any chance you have a storage issue? Failing drive / bad cables? I’ve *never* had an OpenBSD install fail to pass integrity checks.
No as I can rollback to the 14th may or any date before and the upgrade ( downgrade ) all goes fine. Just no snapshot after works on my desktop.

@justine I got a similar error once. I think my issue was the sets and/or the SHA256.sig weren't found automatically.

I had to move them to <version>/<arch>, IIRC

@justine failure to verify downloaded stuff suggests either problems with downloaded files or signing keys. I would first verify the hashes of the download. Try
$ sha256 -C SHA256 *
in the folder that contains the downloaded snapshot files to see if they are corrupted or not.

You can then manually check the signature using signify(1). Something like:

$ signify -C -p /etc/signify/openbsd-79-base.pub -x SHA256.sig *

this is like the previous command but also checks the signature based on the public key provided.

this should tell you whether there is data corruption somewhere, or whether something else, like the pubic keys, got mixed up.

@justine *It has been 0 days since Justine last switched BSDs meme* 🤭
OMG! Has it really been that long?🤣
@justine to be honest I can't keep up any more! 😂

@justine Don't worry. That happens from time to time if you use the CDN. It fails because the signature file was already synced from a newer snapshot and the remaining files are still in transit.

Either wait some time or use a non-CDN mirror.

@justine Possibly dumb thing to try:

Clear out /home/_sysupgrade

Try sysupgrade -s from a different mirror.