Public bug reported: I have a printer connected to WiFi. It appears in Gnome Printers dialog, but printing to that printer does not print: the job is created, never printed, and never completed.
This was a 6-hour-long debugging session that finally found the root of the problem: if a printer exposes IPPS, cups tries to print through that. But if the printer only speaks TLS1.2, a successful connection is never made. I've summarized the entire journey here: https://mvysny.github.io/canon- pixma-cups-tls/ Long story short: ``` # 0. cap TLS for CUPS. NoSystem is not optional - see OpenPrinting/cups#1677 LINE='SSLOptions NoSystem MinTLS1.2 MaxTLS1.2' ls -la ~/.cups/client.conf # must not exist, or it silently wins echo "$LINE" | sudo tee -a /etc/cups/client.conf echo "$LINE" | sudo tee -a /var/snap/cups/common/etc/cups/client.conf sudo systemctl restart cups # or even better, REBOOT # check it from the client side before trusting it ipptool -tv ipps://246989000000.local:631/ipp/print get-printer-attributes.test ``` How to solve this? On LAN, I'd argue that TLS1.2 (or even no TLS at all, going through unencrypted IPP) is okay. So, maybe the solution is to "SSLOptions NoSystem MinTLS1.2 MaxTLS1.3" (if that works; or drop the MaxTLS1.x completely)? ProblemType: Bug DistroRelease: Ubuntu 26.04 Package: cups 2.4.16-1ubuntu1.3 ProcVersionSignature: Ubuntu 7.0.0-30.30-generic 7.0.12 Uname: Linux 7.0.0-30-generic x86_64 ApportVersion: 2.34.1-0ubuntu0.1 Architecture: amd64 CasperMD5CheckResult: pass CurrentDesktop: ubuntu:GNOME Date: Sat Aug 22 19:12:35 2026 InstallationDate: Installed on 2026-04-20 (124 days ago) InstallationMedia: Ubuntu-Server 26.04 "Resolute Raccoon" - Release amd64 (20260420.1) Lpstat: device for Canon_TS5300_series: implicitclass://Canon_TS5300_series/ MachineType: LENOVO 20UH001QMX Papersize: a4 PpdFiles: Error: command ['fgrep', '-H', '*NickName', '/etc/cups/ppd/Canon_TS5300_series.ppd'] failed with exit code 2: grep: /etc/cups/ppd/Canon_TS5300_series.ppd: Permission denied ProcKernelCmdLine: root=/dev/mapper/vg0-lv--0 ro quiet splash crashkernel=2G-4G:320M,4G-32G:512M,32G-64G:1024M,64G-128G:2048M,128G-:4096M ttm.pages_limit=7340032 ttm.page_pool_size=7340032 systemd.machine_id=30ab102fb038416b848e9c8b5f1e412d SnapChanges: ID Status Spawn Ready Summary 114 Done 2026-08-22T17:24:32+03:00 2026-08-22T17:24:32+03:00 Running service command 115 Done 2026-08-22T17:35:46+03:00 2026-08-22T17:35:47+03:00 Running service command SourcePackage: cups UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 03/25/2026 dmi.bios.release: 1.54 dmi.bios.vendor: LENOVO dmi.bios.version: R1CET85W(1.54 ) dmi.board.asset.tag: Not Available dmi.board.name: 20UH001QMX dmi.board.vendor: LENOVO dmi.board.version: SDK0J40697 WIN dmi.chassis.asset.tag: No Asset Information dmi.chassis.type: 10 dmi.chassis.vendor: LENOVO dmi.chassis.version: None dmi.ec.firmware.release: 1.54 dmi.modalias: dmi:bvnLENOVO:bvrR1CET85W(1.54):bd03/25/2026:br1.54:efr1.54:svnLENOVO:pn20UH001QMX:pvrThinkPadT14sGen1:rvnLENOVO:rn20UH001QMX:rvrSDK0J40697WIN:cvnLENOVO:ct10:cvrNone:skuLENOVO_MT_20UH_BU_Think_FM_ThinkPadT14sGen1:pfaThinkPadT14sGen1: dmi.product.family: ThinkPad T14s Gen 1 dmi.product.name: 20UH001QMX dmi.product.sku: LENOVO_MT_20UH_BU_Think_FM_ThinkPad T14s Gen 1 dmi.product.version: ThinkPad T14s Gen 1 dmi.sys.vendor: LENOVO ** Affects: cups (Ubuntu) Importance: Undecided Status: New ** Tags: amd64 apport-bug resolute wayland-session -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2164820 Title: Print job never reaches the printer if it exposes IPPS and only speaks TLS1.2 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/cups/+bug/2164820/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
