I was able to get Yubikey 4 working by reinserting it. Also I checked
and sounds like it works with e.g. U2F and GPG without reinsertion, so
it has some kind of multi-function support.
Closing as Invalid. Sounds like not Ubuntu software problem.
** Changed in: gnupg2 (Ubuntu)
Status: New
Public bug reported:
gpg2 does not work with OpenPGP card:
$ gpg2 --card-status
gpg: selecting openpgp failed: Card error
gpg: OpenPGP card not available: Card error
I also enabled scdaemon debug output and have the following there:
2016-11-14 22:43:49 scdaemon[4817] listening on socket
