On a relatively clean F23 installation (VM installed in March and then mostly ignored), /usr/lib/cups/backend/smb is a symlink to ../../../bin/smbspool (i.e. /usr/bin/smbspool). It isn't supposed to be; it's supposed to point to /etc/alternatives/cups_backend_smb. This means that the samba-krb5-printing package doesn't work.
Hm, cups still has %triggerin -- samba-client ln -sf ../../../bin/smbspool %{cups_serverbin}/backend/smb || : exit 0 So.... we have /usr/libexec/samba/cups_backend_smb which is pointing to the right place via alternatives. But which isn't used. And the one which *does* get used is still pointing unconditionally to plain smbspool.
In order to fix printing with Kerberos tickets using SMB (bug #1273999) I've introduced a new helper binary. The helper binary is called smb_krb5_wrapper and will make sure we switch to the user who issues the print job to get access to the Kerberos credentials cache. For this I packaged smb_krb5_wrapper in a new package called samba-krb5-printing. samba-client still packages smbspool, but it will use update-alternatives to create a symlink: /usr/bin/cups_backend_smb which will point to /usr/bin/smbspool. If the user installs samba-krb5-printing, the updates-alternatives binary will update /usr/bin/cups_backend_smb and point to the wrapper /usr/bin/smb_krb5_wrapper. This way all the cups package has to do is to create a symlink from /usr/lib/cups/backend/smb and point to /usr/bin/cups_backend_smb. samba-krb5-printing requires that samba-client is pre-installed. This way the control to /usr/bin/cups_backend_smb is kept on the Samba side and we will not require changes to cups in the future.
I am currently testing fixed package in RHEL, if it works, I will push it into Fedora rawhide.
cups-2.1.4-1.fc24 has been submitted as an update to Fedora 24. https://bodhi.fedoraproject.org/updates/FEDORA-2016-385435e4ca
cups-2.1.4-1.fc24 has been pushed to the Fedora 24 testing repository. If problems still persist, please make note of it in this bug report. See https://fedoraproject.org/wiki/QA:Updates_Testing for instructions on how to install test updates. You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2016-385435e4ca
cups-2.1.3-2.fc23 has been submitted as an update to Fedora 23. https://bodhi.fedoraproject.org/updates/FEDORA-2016-d82d9ef6f9
cups-2.1.3-2.fc23 has been pushed to the Fedora 23 testing repository. If problems still persist, please make note of it in this bug report. See https://fedoraproject.org/wiki/QA:Updates_Testing for instructions on how to install test updates. You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2016-d82d9ef6f9
cups-2.1.4-1.fc24 has been pushed to the Fedora 24 stable repository. If problems still persist, please make note of it in this bug report.
cups-2.1.3-2.fc23 has been pushed to the Fedora 23 stable repository. If problems still persist, please make note of it in this bug report.