Created attachment 1649949 [details] system-config-printer Troubleshooting output Description of problem: After upgrading to Fedora 31 beta, printing to a networked Epson printer failed with 'Unable to locate printer "EPSON10AD1E.local".' Version-Release number of selected component (if applicable): How reproducible: Printing didn't work, but I didn't try reverting and repeating the upgrade. Steps to Reproduce: 1. Install Epson's driver for WF-3540 printer. 2. Get printing working 3. ??? time passes, upgrade to Fedora 31. 4. Try printing. Actual results: The documents are stuck in the print queue with status 'Unable to locate printer "EPSON10AD1E.local".' Expected results: Printing works. Additional info: I tried reinstalling the printer from KDE printers dialog, and modifying the printer from the (amazing) CUPS admin interface at localhost:631. Nothing helped. If I set cups debug and capture journal output, everything looks fine until cupsd[156258]: [CGI] cgiSetArray: job_printer_state_message[0]="Unable to locate printer "EPSON10AD1E.local"." , which is just reporting the error I see. The printer shows up in `lpinfo -v` as network dnssd://EPSON%20WF-3540%20Series._ipp._tcp.local/?uuid=7c47f900-67ff-11d4-9a7f-b0e89210ad1e network ipp://EPSON10AD1E.local:631/Epson_IPP_Printer CUPS admin showed it was using the dnssd connection; I switched to the IPP connection but that didn't help.
Created attachment 1649950 [details] part of cups log I had the CUPS web admin page open so I think most output comes from that.
I found a fix! https://askubuntu.com/questions/82016/network-printer-found-but-cannot-print/455285#455285 suggests the hosts line in /etc/nsswitch.conf needs to mention mdns, but my file contained only hosts: files dns myhostname https://fedoramagazine.org/find-systems-easily-lan-mdns/ suggests one way to repair this is to remove then reinstall the nss-mdns package. Instead I did `sudo dnf reinstall nss-mdns` which changed the line in /etc/nsswitch.conf to the recommended hosts: files mdns4_minimal [NOTFOUND=return] dns myhostname and then printing worked! I did not install avahi-browse to see if my printer was discoverable before making this fix. RH bug 1577243 discusses how authselect and the nss-mdns package fight over nsswitch.conf , and it sounds like others have had the same problem where an upgrade broke mdns config and thus printing. I have both packages installed; my /etc/nsswitch.conf does not have any mention of authselect and is not a symlink; is is quite different from /etc/authselect/user-nsswitch.conf but both (after I ran `sudo dnf reinstall nss-mdns`) have the identical hosts line with mdns4_minimal. My file sizes and dates are: 1757 2018-08-23 01:44 /etc/authselect/user-nsswitch.conf 1702 2020-01-04 20:30 /etc/nsswitch.conf 1670 2019-09-24 03:30 /etc/nsswitch.conf.bak Documentation: This issue and workaround is not mentioned on https://fedoraproject.org/wiki/How_to_debug_printing_problems (nor does it mention avahi-browse as https://wiki.ubuntu.com/DebuggingPrintingProblems does).
This message is a reminder that Fedora 31 is nearing its end of life. Fedora will stop maintaining and issuing updates for Fedora 31 on 2020-11-24. It is Fedora's policy to close all bug reports from releases that are no longer maintained. At that time this bug will be closed as EOL if it remains open with a Fedora 'version' of '31'. Package Maintainer: If you wish for this bug to remain open because you plan to fix it in a currently maintained version, simply change the 'version' to a later Fedora version. Thank you for reporting this issue and we are sorry that we were not able to fix it before Fedora 31 is end of life. If you would still like to see this bug fixed and are able to reproduce it against a later version of Fedora, you are encouraged change the 'version' to a later Fedora version prior this bug is closed as described in the policy above. Although we aim to fix as many bugs as possible during every release's lifetime, sometimes those efforts are overtaken by events. Often a more recent Fedora release includes newer upstream software that fixes bugs or makes them obsolete.
I've had more problems printing to my %$#@! Epson WF-3540 printer, but not this specific problem with /etc/nsswitch.conf after upgrading to F32, F33, and F34.
Fedora 31 changed to end-of-life (EOL) status on 2020-11-24. Fedora 31 is no longer maintained, which means that it will not receive any further security or bug fix updates. As a result we are closing this bug. If you can reproduce this bug against a currently maintained version of Fedora please feel free to reopen this bug against that version. If you are unable to reopen this bug, please file a new report against the current release. If you experience problems, please add a comment to this bug. Thank you for reporting this bug and we are sorry it could not be fixed.