Suspicious-looking gc profiles root in NixOS 18.03

[Ekdohibs]

Issue description

I installed NixOS 18.03 from a live USB stick on Jun 12, following the manual. When I look at /nix/var/nix/gcroots/profiles, it points to /mnt/nix/var/nix/profiles, which is very suspicious: presumably, this was the location of the profiles during the live USB installation, as per the manual, but is no longer.

$ ls -l /nix/var/nix/gcroots/profiles 
lrwxrwxrwx 1 root root 25 Jun 12 13:55 /nix/var/nix/gcroots/profiles -> /mnt/nix/var/nix/profiles

Shouldn't it be /nix/var/nix/profiles in the destination instead? If so, there might be a problem in the installation script of NixOS.

Steps to reproduce

Didn't try to reproduce, as that would mean installing NixOS again. I guess installing NixOS from a live USB, following the instructions from the manual, would trigger that problem.

Technical details

 - system: `"x86_64-linux"`
 - host os: `Linux 4.14.51, NixOS, 18.03.132750.91b286c8935 (Impala)`
 - multi-user?: `yes`
 - sandbox: `no`
 - version: `nix-env (Nix) 2.0.4`
 - channels(user): `""`
 - channels(root): `"nixos-18.03.132750.91b286c8935, unstable-18.09pre143771.a8c71037e04"`
 - nixpkgs: `/nix/var/nix/profiles/per-user/root/channels/nixos/nixpkgs`

[xeji]

During the installation, did you use nixos-generate-config --root /mnt as documented?

If you omitted the --root /mnt some paths will incorrectly start with /mnt, resulting in a pretty much unusable system. Please paste your generated /etc/nixos/configuration.nix and hardware-configuration.nix if you still have them.

[Ekdohibs]

I am pretty sure I did not omit the --root /mnt.
configuration.nix:
https://paste.tobast.fr/?108f122733477c23#dhg+UhsbzBpALHIzZeksQxb4OlZL7dnbfl2JLPj3ygk=
hardware-configuration.nix:
https://paste.tobast.fr/?b6b5e594f31f2cb6#tbqfPiFcuF1t9pYMcMkEGaKl8fG7oEJeEzE0gJ3bd6E=

[xeji]

Configurations look normal. On my 18.03 system /nix/var/nix/gcroots/profiles doesn't exist. I have no idea what could have caused this. Maybe it disappears after garbage collecting the system? Worth a try.

[stale]

Thank you for your contributions.

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