UPDATE: It’s working again now after rebooting it 4 times. Really strange and happened twice today. Would be really curious to find you how to diagnose this.
nitropy version
0.4.39
Current firmware version: v1.5.0
Nitrokey Pro 3A NFC and Nitrokey Pro 3A Mini
I don’t know how your OS is configuring gpg and scdaemon, but you have to check if it is compiled with CCID support and needs direct access to the hardware via USB or does it need to use pcscd.
If pcscd is installed, there should be automated pcscd activation rule in systemd (socket activation).
To make GPG work with pcscd, you might need disable-ccid in your $HOME/.gnupg/gpg-agent.conf
More about this:
You might need to talk to your distribution maintainers if there are problems.
Thank you for confirming, I think you are right that this is a system related issue and not Nitrokey. Since posting this 2 weeks ago this happened again only once, after kernel update, however this time reboot solved the issue.
Btrfs system snapshots come in very handy as well.