Unforgiving behaviour with broken fingerprint reader
I just updated to Ubuntu 21.04 beta (from 20.10), and encountered a bug making it impossible to sign in with GDM.
The root of the issue is that my ThinkPad's Synaptics fingerprint reader does not natively work on Linux, so I installed a workaround . This workaround did clearly not work in the newer version of GDM. The problem is the behaviour of GDM when confronted with the broken fingerprint reader.
Without me being anywhere near the fingerprint reader, the login screen would inform me that "Sorry, signing in with fingerprint was unsuccessful, please try again". This message would re-appear every few seconds, deleting all text in the password field when it happened. Even when I wrote my password and pressed enter before it deleted my input, the message would appear and cancel the sign-in procedure. After this the password field would be unresponsive for a while.
In the end, I signed in with ctrl+alt+F2, uninstalled open-fprintd, and installed fprintd. This seems to have solved the problem for now. However, GDM should allow users to sign in with a password no matter how the fingerprint reader is (mis)behaving.
To reproduce on a ThinkPad with the Synaptics reader in question, these seem to be the necessary steps:
- Install python-validity (maybe only open-fprint is needed)
sudo apt remove fprintd sudo add-apt-repository ppa:uunicorn/open-fprintd sudo apt-get update sudo apt install open-fprintd fprintd-clients python3-validity
- Reboot, attempt to sign in.
I am happy to report which version of GDM I'm on, but I'm too incompetent to figure it out.
I also updated to Gnome 40 after encountering the issue once, and then managing to sign in once after a crash. I had the same problem in Gnome 40 as in 3.38, so it's not related to this.
Thanks for your work! :)