Missing backends and devices

[Angus Mackenzie]

> I have an AMD64 system running 64-bit Debian, with kernel 2.6.8-10-amd64-k8, which I think arrived by automatic update about a week ago. At roughly the same time, the usb connected Epson CX5400 stopped working.
>
> When I try to add a printer with the web interface, only the SMB (windows) and Other backends are selectable, though there are about eleven files in the backends .../lib/cups/backends directory
>
> lpinfo -v reveals only direct canon, epson and cups-pdf devices. I tried temporarily hiding these backends but then there are no devices (Duh)
>
> The logs are unhelpful, even when turned up to debug (haven't tried debug2). So I guess my question would be; is this a hardware discovery issue from boot time, or does some other magic happen to populate the output of lpinfo -v and the backend selection?
>

Following myself up; eventually I have inspected the backend file permissions. None of the missing ones are executable (permission denied). I guess that would explain why they are unavailable.

Any suggestions as to how this curious state of affairs came about?

FWIW, my CUPS version is 1.1.23.

Angus Mackenzie