I've set up greetd and agreety on Void Linux. The _greeter user exists, and I've activated the greetd service. Also activated are the dbus and polkitd services.
When agreety loads, I can't type, or can only type erratically, it doesn't appear to recognise my password, and after a few attempts, it shows the error "client loop failed: i/o error: Broken pipe (os error 32)".
Here's a video of what happens (apologies for the shaky camera work!): https://photos.app.goo.gl/iFyLcj1BLcsSihQu6
The same problems occur on tuigreet, but they look rather more broken.
I am only able to log in by switching to another TTY. There, I can log in fine.
You are probably still running (a)getty on that TTY, leading to agetty and agreety fighting to be the one to read a keyboard press. Disable (a)getty and try again.
This indeed appeared to be the case, thank you. I ran into unrelated problems and couldn't finish getting agreety to work, so this can be closed if you like!