k3b installed locally for users to burn CDs/DVDs/etc. This only gets used very infrequently, and it seems that something else has broken every time it does get used.
This time it was a “Cannot find writer” error. I checked for the presence of cdrecord and dvd-rw-tools; all fine. Eventually it turned out to be a permissions error - that
/dev/cdrom was set to be only user- and group-writable; and the user was not in the relevant group. Added them, log in & out, all well.
This is curious, because I am 100% confident that I haven’t changed anything on either
/dev/cdrom (or the relevant group membership). Which implies that it has been changed with an update at some point. I’m not sure I see the point of this. Is being able to write to
/dev/cdrom really such a security risk?
The longer-term solution is (assuming this doesn’t break anything; I haven’t checked yet) to set the cdrom group to come from LDAP and automatically put all users in it, to avoid having to do this for multiple machines.