Unable to locate printer (on the network) - Brother HL-3170CDW

[Christian Gelinek]

Hi all,

I am rather new to GuixSD and don't have much experience with GNU/Linux 
printing, so please bear with me.

Trying to set up my Brother HL-3170CDW series printer over the network I 
found some useful messages on this list, especially the example system 
configuration at
https://lists.gnu.org/archive/html/help-guix/2020-05/txtEOQnSAKbJY.txt
which I took as a reference when extending my own config file.

I got the CUPS web GUI working, which detects the printer in the Add 
Printer dialog, with a Connection setting of 
dnssd://Brother%20HL-3170CDW%20series._ipp._tcp.local/?uuid=e3248000-80ce-11db-8000-001ba9fa9f52

When trying to print a test page, the State column on the printer's 
page's Jobs section becomes "Unable to locate printer 
"BRN001BA9FA9F52.local"."

On another system running Xubuntu 18.04, I can successfully print on the 
same printer using a different connection, namely
ipp://BRN001BA9FA9F52.local:631/ipp/printer.

So I set up another printer in the GuixSD's CUPS GUI with the same 
connection, but unfortunately it keeps giving me the same error when I 
attempt to print a test page.

Any help with fixing or debugging this further would be much appreciated.

Thanks,
Christian