Unverified Commit 6c7ad5e7 authored by emilylange's avatar emilylange
Browse files

nixos/systemd-lib: fix building of empty unit files 

This is a fixup for c1ae82f4.

nix' `passAsFile` does not create empty files for variables that are
`null`.

This results in the following error for units that have no overrides or
content, but are, e.g. `wantedBy`:
`mv: cannot stat '': No such file or directory`.

Minimal reproducer:
`systemd.units.empty.wantedBy = [ "multi-user.target" ];`

This is often necessary when a unit is loaded in via `systemd.packages`.
parent 90b0f71e

nixos/lib/systemd-lib.nix

+4 −1
Original line number Diff line number Diff line
@@ -20,7 +20,10 @@ in rec { 
      pkgs.runCommand "unit-${mkPathSafeName name}"

        { preferLocalBuild = true;

          allowSubstitutes = false;

          inherit (unit) text;

          # unit.text can be null. But variables that are null listed in

          # passAsFile are ignored by nix, resulting in no file being created,

          # making the mv operation fail.

          text = optionalString (unit.text != null) unit.text;

          passAsFile = [ "text" ];

        }

        ''