It seems that with the latest update to `udisks2`, the ExecStart path
for the daemon changed from `/lib/udisks2` to `/libexec/udisks2`. This
commit reflects that change for our purposes.
If a kernel without CONFIG_UEVENT_HELPER set is used with NixOS, the file
/proc/sys/kernel/hotplug does not exist. Before writing to it to disable
this deprecated mechanism, we have to ensure it actually exists because
otherwise the activation script will fail.
From http://www.freedesktop.org/wiki/Software/systemd/PredictableNetworkInterfaceNames/
You disable the assignment of fixed names, so that the unpredictable
kernel names are used again. For this, simply mask udev's rule file for
the default policy: ln -s /dev/null
/etc/udev/rules.d/80-net-setup-link.rules (since v209: this file was
called 80-net-name-slot.rules in release v197 through v208)
From http://www.freedesktop.org/wiki/Software/systemd/PredictableNetworkInterfaceNames/
You disable the assignment of fixed names, so that the unpredictable
kernel names are used again. For this, simply mask udev's rule file for
the default policy: ln -s /dev/null
/etc/udev/rules.d/80-net-setup-link.rules (since v209: this file was
called 80-net-name-slot.rules in release v197 through v208)
Option defaults should not refer to store paths, because they cause
the manual to be rebuilt gratuitously. It's especially bad to refer to
a highly variable path like a computed configuration file.
The ability for unprivileged users to mount external media is useful
regardless of the desktop environment. Also, since udisks2 is
activated on-demand, it doesn't add any overhead if you're not using it.
If you define a unit, and either systemd or a package in
systemd.packages already provides that unit, then we now generate a
file /etc/systemd/system/<unit>.d/overrides.conf. This makes it
possible to use upstream units, while allowing them to be customised
from the NixOS configuration. For instance, the module nix-daemon.nix
now uses the units provided by the Nix package. And all unit
definitions that duplicated upstream systemd units are finally gone.
This makes the baseUnit option unnecessary, so I've removed it.
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.
