Here's my Linux curiosity of the moment.
Apparently there are a fair number of applications out there that like to use the GNOME keyring to store logins. Ordinarily the login keyring is unlocked when you enter your password.
However: what if you're running a passwordless system with a Yubikey, smart card, facial recognition, anal probe, or whatever? In that case, the keyring doesn't unlock when you unlock the computer, because it is literally expecting a
password only, not a "credential" generally speaking.
Some guy made a workaround here:
Essentially: encrypt a keyring/password pair (not necessarily related to any user's password) on disk with GnuPG, set up your 2FA device as a GPG smart card, and then set up scripts to automatically decrypt the file with the smart card and pipe the result into the keyring unlock process whenever you unlock your machine.
It's clever but it rubs me the wrong way.