Temporarily remove automatic printer discovery

cups-browsed is the daemon that watches the network and creates print queues by itself. Hardening it took a root daemon with a predictable cache down to a confined service account, but a daemon that turns anything advertising itself on the network into a print queue is a lot of exposure for a convenience, so it comes out of the default install while that is reworked. Only the discovery half: CUPS itself stays and printing keeps working, with each printer added by hand in Print Settings.

The migration disables the unit before removing the package because that is the only order that works: pacman deletes the unit file but not the enable symlink, and once the unit is gone systemd can no longer resolve it by name to clean that up.

It then removes the queues discovery generated. cups-browsed keeps those when it stops, since KeepGeneratedQueuesOnShutdown defaults to Yes, and they route through its own implicitclass backend, which goes with the package, so they cannot print again. Idle ones go. A queue with jobs on it is left alone and named: implicitclass only needs cups-browsed to choose a destination, so a job already past that point finishes on its own, and deleting the queue would abort it. One printer's job does not hold up the removal. A printer added by hand has an ipp:// or usb:// device and is left where it is.

A queue whose jobs cannot be asked about is left alone rather than assumed idle, including one named so that lpstat would misread it -- "all" is its word for every destination, and a leading dash or a comma reads as another option or a list.

Where CUPS does not answer at all, or a queue will not delete, discovery is still stopped but the package stays and no marker is written. omarchy-migrate records a migration for the user as soon as it exits zero, so that is where the machine stays until someone removes the package by hand, and the message says so rather than implying a retry.

The queue list is read under LC_ALL=C because lpstat translates "device for", and captured rather than piped, so a cupsd it cannot reach is reported instead of reading like a machine with nothing to clean up.

It removes with plain pacman -R rather than omarchy-pkg-drop, which passes -n and would discard /etc/cups/cups-browsed.conf instead of keeping it as a .pacsave. A removal meant to be temporary should not delete the machine's copy of its own configuration. Without -s either, so it only ever removes the package it names: sweeping newly unneeded dependencies is nothing today, but it is not a promise a rolling dependency graph can keep.

Queue names come off the network, since cups-browsed names its queues after what the printer advertised. CUPS allows every printable character but space, tab, / and #, and lpstat and lpadmin take a destination as an option value, so a name with a leading dash or a comma is reported rather than passed to them and guessed at.

Migration state is per user, so a machine-wide marker records the one removal. Without it, an account whose first migration run came after someone deliberately reinstalled discovery would quietly take it back out again.

The install-time override for cups-browsed.conf now waits for cups-browsed rather than for CUPS. Guarding it on a file CUPS still ships would write a configuration file for a package nothing installed, and pacman would later land the package's own copy beside it as a .pacnew.

The hardened configuration stays in the tree. omarchy-settings still ships the cups-browsed.conf override, the sysusers account and the service drop-in, so they are what discovery returns onto.

Co-Authored-By: Codex XHigh <noreply@openai.com>
This commit is contained in:
David Heinemeier Hansson
2026-08-29 17:13:11 +02:00
co-authored by Codex XHigh
parent 0b3f1b7ead
commit 24c18df5b7
9 changed files with 563 additions and 67 deletions
+7 -1
View File
@@ -44,7 +44,13 @@ The plain open source Chromium build doesn't ship with the OAuth credentials tha
### How do I add a printer?
Printing is set up and running out of the box, so a printer on your network is usually already discovered. Launch _Print Settings_ from the app launcher (`Super + Space`) to see what's there, add one by hand, or set the default. Printing to a PDF file works without any printer at all.
Printing is set up and running out of the box, and you add each printer yourself from _Print Settings_ in the app launcher (`Super + Space`).
Choose _Add_, and give it a moment to look: a printer plugged in over USB, and most network printers, are found for you. If yours isn't in the list, pick _Network Printer > Internet Printing Protocol (ipp)_ and enter its address — the printer's own display or its web page will tell you what that is, usually something like `192.168.1.50` with a queue of `ipp/print`. _Forward_ then offers a driver, where a modern printer works best on the driverless _IPP Everywhere_ profile and an older one wants the model's own driver.
Right-click a printer and choose _Set as Default_ to pick which one your apps reach for first, and _Properties_ to set paper size, duplex and quality.
Automatic discovery, where printers on the network appear without being added, is temporarily switched off while it's reworked, which is why the first step above is yours rather than automatic. Printing to a PDF file works without any printer at all.
### How do I change where screenshots or screenrecordings are saved?