brew upgrade pulumi throws an Error: invalid attribute for formula ‘pulumi/tap/pulumi’: version, I opened a bug report at brew, https://github.com/Homebrew/homebrew-core/issues/112439, but they said it’s a 3rd party tap and open a bug here.

There are two pulumi homebrew setups, one in homebrew-core and one from our own tap. Looks like the last release didn't correctly update our one, I'll get that fixed now.

Thanks for the quick fix. All working as expected now.