Currently, default options for media-session are empty, making it harder
to adapt them without fully overwriting them. This commit sets these
defaults to the content of the JSON files provided with media-session.
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
```
tracker looks in its directory tree for executable files
to make available as subcommands. Users expect to find subcommands
from tracker-miners package but that fails as they are in different
tree. We also cannot change the lookup path since tracker-miners
also depends on a library from tracker package.
Until we can break the dependency cycle on package level:
tracker -> tracker-miners -> tracker-sparql (tracker)
we need to work around it. I chose to set an environment
variable that overrides the subcommands lookup to a tree
symlinking files from both packages in GNOME NixOS module.
https://gitlab.gnome.org/GNOME/tracker/-/issues/341
Fixes: https://github.com/NixOS/nixpkgs/issues/153378
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.
