Re: Color calibrating scanner with GNOME

[Jack Hill <jackhill@jackhill.us>]

On Sat, 16 Mar 2019, Jack Hill wrote:

> Hi Guix,
>
> I'm trying to color calibrate my scanner while running GNOME by following 
> these instructions: 
> https://help.gnome.org/users/gnome-help/stable/color-calibrate-scanner.html.en
>
> I have produced a tiff of my calibration target, but my scanner doesn't show 
> up in the GNOME settings color submenu. The only device show is my laptop 
> screen.
>
> GNOME's simple-scan and sane-backend's* scanimage can use the scanner, and 
> scanimage reports it as:
>
> $ scanimage -L
> device `pixma:MF4800_Canon5e5c59' is a CANON Canon i-SENSYS MF4800 Series 
> multi-function peripheral
>
> The device is connected over the network.
>
> What should I do to try to calibrate my scanner?

I've done some more troubleshooting:

I installed GNOME 3.30 (newer GNOME than current Guix master) on a Debian 
10 (buster, testing) host. The scanner did not show up in the calibration 
dialog when connecting over the network. I suspect that this is because 
GNOME hardware/calibration does not trigger the search of the network for 
scanners. When I plugged it in via USB, it did show up in the calibration 
dialog. (Unfortunately, it doesn't scan over USB because of some as yet 
undetermined bug in sane or the device firmware (I'm extra suspicious of 
it because it is a multi-function device, so I imagine is more complex.).)

On Guix, when the scanner is connected via USB it cannot be found by my 
user's scanning programs (or, therefore, the GNOME hardware/calibration 
dialog). However, it can be found as root. I suspect the problem is a 
missing udev rule. What is the right way to proceed?

Best,
Jack