keepassxc-cli has no option to open a database which requires a Yubikey challenge.
There is no way to use keepassxc-cli with a Yubikey protected database.
Only passwords and key files are accepted.
Add a commandline flag indicating what key or slot to use, which will enable Yubikey challenge/response authentication for the command line tool.
Attempt to open a Yubikey protected database using keepassxc-cli
I am unable to use keepassxc-cli to handle merging or backup exports (which I would then GPG encrypt to an offline key) once a Yubikey is enabled.
$ keepassxc-cli -v
2.3.4
Operating system: Ubuntu Xenial
CPU architecture: amd64
Kernel: 4.15.0-36-generic
Enabled extensions:
This was implemented by https://github.com/keepassxreboot/keepassxc/pull/3416
Many thanks, all!
Most helpful comment
This was implemented by https://github.com/keepassxreboot/keepassxc/pull/3416