Todd A. Jacobs | Pragmatic Cybersecurity#macOS broke #scdaemon and support for certain #ccid devices a few iterations ago, but if you're running Sonoma or are using @GPGTools you have to make some changes to your PATH, gpg.conf, gpg-agent.conf, and scdaemon.conf files to get #GPG working with a @yubico #YubiKey. Otherwise, no matter what you do, GPG won't be able to recognize the YubiKey properly, or access the key material stored on it.
This is basically the result of macOS "forcing" the use of its native #PCSC #daemon, which conflicts with the GPG #scdaemon. In addition, if you use both #GPGTools and a version of GPG installed via #Homebrew you will need to ensure that the non-Homebrew version is first in your PATH even for #CLI stuff.
This is apparently a known issue, and has been for a while, but it's hard to find the solution if you don't know exactly what to look for. The fixes require a bit of cargo-cult configuration changes; I haven't managed to fine it down to the smallest set of necessary changes yet, and this one doesn't cover the shell updates, so feel free to post a link of you know of a better starting point than this one.
