Of course, you'll get a bunch of warnings from the activation script:
$ nixos-enter --root /tmp/mnt/
setting up /etc...
mount: /dev: permission denied.
mount: /dev/pts: permission denied.
mount: /dev/shm: permission denied.
mount: /sys: permission denied.
/nix/var/nix/profiles/system/activate: line 74: /proc/sys/kernel/modprobe: Permission denied
chown: changing ownership of '/run/wrappers/wrappers.0pKlU8JsvV/dbus-daemon-launch-helper': Invalid argument
NOTE: Under Linux, effective file capabilities must either be empty, or
exactly match the union of selected permitted and inheritable bits.
Failed to set capabilities on file `/run/wrappers/wrappers.0pKlU8JsvV/ping' (Operation not permitted)
chown: changing ownership of '/run/wrappers/wrappers.0pKlU8JsvV/unix_chkpwd': Invalid argument
[root@nixos:/]#
The use of Nix 2.0 significantly simplifies the installer, since we
can just pass a different store URI (--store /mnt) - it's no longer
needed to set up a chroot environment for the build, and to bootstrap
Nix into the chroot.
Also, commands that need to run in the installation (namely boot
loader installation and setting a root password) are now executed
using nixos-enter.
This also removes the need for nixos-prepare-root since any required
initialisation is done by Nix or by the activation script.
* The environment variables NIX_CONF_DIR, NIX_BUILD_HOOK and
NIX_REMOTE are no longer needed.
* A /bin/sh (from busybox) is provided by default in sandboxes.
* Various options were renamed.
Among other things, this will allow *2nix tools to output plain data
while still being composable with the traditional
callPackage/.override interfaces.
This can be disabled with the `withKerberos` flag if desired.
Make the relevant assertions lazy,
so that if an overlay is used to set kerberos to null,
a later override can explicitly set `withKerberos` to false.
Don't build with GSSAPI by default;
the patchset is large and a bit hairy,
and it is reasonable to follow upstream who has not merged it
in not enabling it by default.
This can be disabled with the `withKerberos` flag if desired.
Make the relevant assertions lazy,
so that if an overlay is used to set kerberos to null,
a later override can explicitly set `withKerberos` to false.
Don't build with GSSAPI by default;
the patchset is large and a bit hairy,
and it is reasonable to follow upstream who has not merged it
in not enabling it by default.