I know this post is dated but I ran into the exact same scenario you’re experiencing, so I hope these steps help:
Use the AppImage to clear any previously stored fingerprints (optional)
^ might require libfuse2 if not already installed
Next, completely remove fprintd
sudo apt remove --purge fprintd
clean up anything left over
sudo apt autoremove --purge
Then, install the following package:
sudo apt install libpam-fprintd
this should automatically hit the fprintd meta package and install any dependencies.
Next make sure it’s started
sudo systemctl status fprintd.service
if it ain’t green (active) then restart it
sudo systemctl restart fprintd.service
Enroll your fingerprint:
fprintd-enroll
after it shows completed run the following (DO NOT TEST IT OUT YET, PATIENCE!)
sudo pam-auth-update
select Fingerprint Authentication and Ok
Reboot your machine
Try and login with your fingerprint
Try “sudo” from terminal and see if it prompts/accepts your fingerprint
Try launching a GUI app that requires sudo and see if it works
I’m not an expert, your mileage may vary. I just recently picked up the Framework i7-1280P and have been tooling around with it for a few days. IMO is a solid rig and will be a well suited replacement.
I wrote the steps out specifically because I wasted half a day installing it how you expect to install it “sudo apt install fprintd” with no successful results (in fact I invoked a known bug where I couldn’t login through GDM) so please follow the steps as written.
PS: The result will show the stored fingerprint in the GUI
But I would strongly advise AGAINST using the GUI for this. There’s definitely something going on there
I’m sure there is a way to declare/name a fingerprint that you are enrolling, I am just too lazy to read the man for fprintd