For a user to be able to scan with an USB scanner, it must have write access
to the corresponding file in /dev/bus/usb. Enabling the sane module
adds SANE's upstream hwdb file and udev rules to udev search path. The
hwdb file tags the scanner as `libsane_matched` and a builtin (from
systemd upstream) udev rule marks all `libsane_matched` devices as
uaccess. When a physical user logins, logind adds an acl allowing them
to write to the device.
Unfortunately, saned is a daemon. Therefore, uaccess has no effect for
it, and if no other udev rule changes the device to belong to the
scanner group or the lp group, (there are such rules, but they are not
complete enough, in that some scanners known by SANE rules are not known
by these rules), it will not be able to write to the scanner.
This solves this by adding a udev rule so that all libsane_matched
devices have an acl rules so that users in the scanner group can write.
A similar rule is present on Arch and Debian at least.
Note that we don't chgroup the file instead, because this posed problems
in the past: scanners are often also printers, and a device's group
cannot be simultaneously lp and scanner.
Fixes: https://github.com/NixOS/nixpkgs/issues/361981
After final improvements to the official formatter implementation,
this commit now performs the first treewide reformat of Nix files using it.
This is part of the implementation of RFC 166.
Only "inactive" files are reformatted, meaning only files that
aren't being touched by any PR with activity in the past 2 months.
This is to avoid conflicts for PRs that might soon be merged.
Later we can do a full treewide reformat to get the rest,
which should not cause as many conflicts.
A CI check has already been running for some time to ensure that new and
already-formatted files are formatted, so the files being reformatted here
should also stay formatted.
This commit was automatically created and can be verified using
nix-build a08b3a4d19.tar.gz \
--argstr baseRev b32a094368
result/bin/apply-formatting $NIXPKGS_PATH
these changes were generated with nixq 0.0.2, by running
nixq ">> lib.mdDoc[remove] Argument[keep]" --batchmode nixos/**.nix
nixq ">> mdDoc[remove] Argument[keep]" --batchmode nixos/**.nix
nixq ">> Inherit >> mdDoc[remove]" --batchmode nixos/**.nix
two mentions of the mdDoc function remain in nixos/, both of which
are inside of comments.
Since lib.mdDoc is already defined as just id, this commit is a no-op as
far as Nix (and the built manual) is concerned.
This brings back the ability to e.g. configure sane-airscan with
`environment.etc."sane.d/airscan.conf".text = ...`.
(AFAICT, sane-airscan loads all config files it finds, so it'll first
load the one from the nixos hardware.sane.* configuration, then the user
specified one in /etc/sane.d/airscan.conf.)
Fixes: 4fbec87a5b ("nixos/sane: point env vars to /etc for quick reload")
Fixes https://github.com/NixOS/nixpkgs/issues/207262
It's a very useful backend (that probably should be enabled by default,
like on Ubuntu), let's start by making it easier to discover.
Ref https://github.com/NixOS/nixpkgs/issues/28406.
Point $SANE_CONFIG_DIR and $LD_LIBRARY_PATH to symlinks in /etc, instead
of directly to nix store paths, so that activating a new configuration
takes effect immediately, instead of requiring users to re-login.
the conversion procedure is simple:
- find all things that look like options, ie calls to either `mkOption`
or `lib.mkOption` that take an attrset. remember the attrset as the
option
- for all options, find a `description` attribute who's value is not a
call to `mdDoc` or `lib.mdDoc`
- textually convert the entire value of the attribute to MD with a few
simple regexes (the set from mdize-module.sh)
- if the change produced a change in the manual output, discard
- if the change kept the manual unchanged, add some text to the
description to make sure we've actually found an option. if the
manual changes this time, keep the converted description
this procedure converts 80% of nixos options to markdown. around 2000
options remain to be inspected, but most of those fail the "does not
change the manual output check": currently the MD conversion process
does not faithfully convert docbook tags like <code> and <package>, so
any option using such tags will not be converted at all.
Whenever I try to scan from another computer it has to establish >2
connections in order to succeed. With the connections being limited to 1
I can not scan any document.
This is also what other distributions ([Debian], [ArchLinux], …) have
done in one way or another.
[Debian]: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=850649#5
[ArchLinux]: no limit: 99cba454bb/trunk/saned.socket (L4)
Using pkgs.lib on the spine of module evaluation is problematic
because the pkgs argument depends on the result of module
evaluation. To prevent an infinite recursion, pkgs and some of the
modules are evaluated twice, which is inefficient. Using ‘with lib’
prevents this problem.
