config instructions for commit signing with ssh keys

[GrumpyOldTroll]

Code of Conduct

• I have read and agree to the GitHub Docs project's Code of Conduct

What article on docs.github.com is affected?

https://docs.github.com/en/authentication/managing-commit-signature-verification/telling-git-about-your-signing-key#telling-git-about-your-ssh-key

What part(s) of the article would you like to see updated?

When I use the path to my public key, my commits are unverified.

So this config has broken behavior for me:

git config --global user.signingkey /PATH/TO/.SSH/KEY.PUB

When I changed it to use the contents of the public key file, my signatures became verified as long as the private key was added to the ssh-agent with ssh-add.

So using this config instead of the above fixed the instructions for me:

git config --global user.signingkey "$(cat /PATH/TO/.SSH/KEY.PUB)"
ssh-add /PATH/TO/.SSH/KEY

Also useful here would be an explanation (if the feature exists?) that describes how to cause a visible warning or error if commit-signing is enabled but a particular signing of a commit was unsuccessful.

Additional information

This is on an up-to-date macbook, in case it matters. I haven't verified the same problem on other platforms.

git --version
git version 2.50.1 (Apple Git-155)