unknown command "attestation" for "gh"

Question

I was trying to upgrade all Homebrew packages with

brew upgrade

and encountered the following error:

unknown command "attestation" for "gh"

Answer 1

I hadn't updated or upgraded Homebrew in a while. I updated Homebrew first using

brew update

and then tried to upgrade all packages. It appears brew is using gh attestation now, but the version of gh I had installed did not have this subcommand.

To fix this, I manually upgraded gh first, and then upgraded all packages:

brew upgrade gh
brew upgrade