nixos-upgrade.service can't exec su: No such file or directory

[8573]

Issue description

In the systemd journal for nixos-upgrade.service, I notice error messages about being unable to find the program su:

systemd[1]: Starting NixOS Upgrade...
jz91zw8nmyzvdbb0w6mqvfhsmx8195zk-unit-script-nixos-upgrade-start[20020]: unpacking 'https://nixos.org/channels/nixos-unstable/nixexprs.tar.xz'...
jz91zw8nmyzvdbb0w6mqvfhsmx8195zk-unit-script-nixos-upgrade-start[20020]: warning: Nix search path entry '$HOME/.nix-defexpr/channels' does not exist, ignoring
jz91zw8nmyzvdbb0w6mqvfhsmx8195zk-unit-script-nixos-upgrade-start[20020]: building Nix...
jz91zw8nmyzvdbb0w6mqvfhsmx8195zk-unit-script-nixos-upgrade-start[20020]: warning: Nix search path entry '$HOME/.nix-defexpr/channels' does not exist, ignoring
jz91zw8nmyzvdbb0w6mqvfhsmx8195zk-unit-script-nixos-upgrade-start[20020]: building the system configuration...
jz91zw8nmyzvdbb0w6mqvfhsmx8195zk-unit-script-nixos-upgrade-start[20020]: warning: Nix search path entry '$HOME/.nix-defexpr/channels' does not exist, ignoring
nixos[21622]: switching to system configuration /nix/store/dvc3aq1rlyddjbc50si8sjfcrc9f9ga9-nixos-system-[hostname]-19.03pre153158.7df10f388da
jz91zw8nmyzvdbb0w6mqvfhsmx8195zk-unit-script-nixos-upgrade-start[20020]: activating the configuration...
jz91zw8nmyzvdbb0w6mqvfhsmx8195zk-unit-script-nixos-upgrade-start[20020]: setting up /etc...
jz91zw8nmyzvdbb0w6mqvfhsmx8195zk-unit-script-nixos-upgrade-start[20020]: reloading user units for root...
jz91zw8nmyzvdbb0w6mqvfhsmx8195zk-unit-script-nixos-upgrade-start[20020]: Can't exec "su": No such file or directory at /nix/store/dvc3aq1rlyddjbc50si8sjfcrc9f9ga9-nixos-system-[hostname]-19.03pre153158.7df10f388da/bin/switch-to-configuration line 422, <$listActiveUsers> line 1.
jz91zw8nmyzvdbb0w6mqvfhsmx8195zk-unit-script-nixos-upgrade-start[20020]: reloading user units for c74d...
jz91zw8nmyzvdbb0w6mqvfhsmx8195zk-unit-script-nixos-upgrade-start[20020]: Can't exec "su": No such file or directory at /nix/store/dvc3aq1rlyddjbc50si8sjfcrc9f9ga9-nixos-system-[hostname]-19.03pre153158.7df10f388da/bin/switch-to-configuration line 422, <$listActiveUsers> line 2.
jz91zw8nmyzvdbb0w6mqvfhsmx8195zk-unit-script-nixos-upgrade-start[20020]: setting up tmpfiles
nixos[21622]: finished switching to system configuration /nix/store/dvc3aq1rlyddjbc50si8sjfcrc9f9ga9-nixos-system-[hostname]-19.03pre153158.7df10f388da
systemd[1]: Started NixOS Upgrade.

I note that most other executables invoked in this switch-to-configuration script seem to be invoked by absolute store paths, whereas it invokes su as simply su.

Steps to reproduce

Use nixos-upgrade.service (system.autoUpgrade.enable = true in configuration.nix) and check its journal entries (journalctl -eu nixos-upgrade.service as the superuser).

Technical details

• system: "x86_64-linux"
• host os: Linux 4.14.59, NixOS, 19.03pre153158.7df10f388da (Koi)
• multi-user?: yes
• sandbox: yes
• version: nix-env (Nix) 2.1.2
• channels(root): "nixos-19.03pre152634.218ce4de508"
• nixpkgs: /nix/var/nix/profiles/per-user/root/channels/nixos

[stale]

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[8573]

I no longer seem to have this issue.

@alunduil: I see that you "thumbs-upped" my issue report. Do you still have this issue?

[alunduil]

Nope, I haven't seen this in a while either. I think it can safely be closed.