In https://gitlab.gnome.org/GNOME/gnome-settings-daemon/-/merge_requests/153
the user target names for GSD components has been renamed for example
from `gsd-a11y-settings.target` to `org.gnome.SettingsDaemon.A11ySettings.target`,
and nowadays `gsd-*.target` are just symbolic links of `/dev/null` and will be
removed in the future.
At the same time, as mentioned in d27212d466,
we are adding `systemd.user.targets.<name>.wants` stuff here only because
systemd.packages doesn't pick the .wants directories. Nowadays those GSD components
are managed in `/etc/systemd/user/gnome-session@gnome.target.d/gnome.session.conf`
so it should be safe to remove them.
In this commit we also try to pick up those new .wants directories, see also
https://gitlab.gnome.org/GNOME/gnome-settings-daemon/-/blob/41.0/plugins/meson.build#L57
Result of `cd /nix/store/iqzy2a6wn9bq9hqx7pqx0a153s5xlnwp-gnome-settings-daemon-41.0; find | grep wants`:
```
./share/systemd/user/gnome-session-x11-services-ready.target.wants
./share/systemd/user/gnome-session-x11-services-ready.target.wants/org.gnome.SettingsDaemon.XSettings.service
./share/systemd/user/gnome-session-x11-services.target.wants
./share/systemd/user/gnome-session-x11-services.target.wants/org.gnome.SettingsDaemon.XSettings.service
```
Result of `cd /nix/store/armzljlnsvc1gn0nq0bncb9lf8fy32zy-gnome-settings-daemon-3.34.0; find | grep wants`:
```
./lib/systemd/user/gnome-session-initialized.target.wants
./lib/systemd/user/gnome-session-initialized.target.wants/gsd-a11y-settings.target
./lib/systemd/user/gnome-session-initialized.target.wants/gsd-color.target
./lib/systemd/user/gnome-session-initialized.target.wants/gsd-datetime.target
./lib/systemd/user/gnome-session-initialized.target.wants/gsd-power.target
./lib/systemd/user/gnome-session-initialized.target.wants/gsd-housekeeping.target
./lib/systemd/user/gnome-session-initialized.target.wants/gsd-keyboard.target
./lib/systemd/user/gnome-session-initialized.target.wants/gsd-media-keys.target
./lib/systemd/user/gnome-session-initialized.target.wants/gsd-screensaver-proxy.target
./lib/systemd/user/gnome-session-initialized.target.wants/gsd-sharing.target
./lib/systemd/user/gnome-session-initialized.target.wants/gsd-sound.target
./lib/systemd/user/gnome-session-initialized.target.wants/gsd-smartcard.target
./lib/systemd/user/gnome-session-initialized.target.wants/gsd-wacom.target
./lib/systemd/user/gnome-session-initialized.target.wants/gsd-print-notifications.target
./lib/systemd/user/gnome-session-initialized.target.wants/gsd-rfkill.target
./lib/systemd/user/gnome-session-initialized.target.wants/gsd-wwan.target
./lib/systemd/user/gnome-session-x11-services.target.wants
./lib/systemd/user/gnome-session-x11-services.target.wants/gsd-xsettings.target
```
most modules can be evaluated for their documentation in a very
restricted environment that doesn't include all of nixpkgs. this
evaluation can then be cached and reused for subsequent builds, merging
only documentation that has changed into the cached set. since nixos
ships with a large number of modules of which only a few are used in any
given config this can save evaluation a huge percentage of nixos
options available in any given config.
in tests of this caching, despite having to copy most of nixos/, saves
about 80% of the time needed to build the system manual, or about two
second on the machine used for testing. build time for a full system
config shrank from 9.4s to 7.4s, while turning documentation off
entirely shortened the build to 7.1s.
It was basically just a `environment.systemPackages` synonym,
only GNOME used it, and it was stretching the responsibilities
of the flatpak module too far.
It also makes it cleaner to avoid installing the program
using GNOME module’s `excludePackages` option.
Partially reverts: https://github.com/NixOS/nixpkgs/pull/101516
Fixes: https://github.com/NixOS/nixpkgs/issues/110310
(It was requested by them.)
I left one case due to fetching from their personal repo:
pkgs/desktops/pantheon/desktop/extra-elementary-contracts/default.nix
The upstream pipewire config is written in an almost, but not quite
JSON format. The parser accepts standard JSON, though, so we don't
need to write our file in the same nonstandard version.
The typing for all config options is changed from `types.attrs`, which
behaves poorly when the option is set from multiple locations, to the
formats.json-type.
Also, rewrite some very long one-liners for improved readability.
