nixos/systemd: make sure all the device nodes are created in stage1

[K900]

Description of changes

The ConditionFileNotEmpty override patch wasn't correct for stage1, which does have the modules in /lib. So, remove the condition instead, and set the right path with overrides in both stage1 and the final system.

Also, make sure systemd-tmpfiles-setup-dev is pulled in to create all the necessary symlinks.

Unfortunately requires a systemd rebuild.

Things done

• Built on platform(s)
  • x86_64-linux
  • aarch64-linux
  • x86_64-darwin
  • aarch64-darwin
• For non-Linux: Is sandbox = true set in nix.conf? (See Nix manual)
• Tested, as applicable:
  • NixOS test(s) (look inside nixos/tests)
  • and/or package tests
  • or, for functions and "core" functionality, tests in lib/tests or pkgs/test
  • made sure NixOS tests are linked to the relevant packages
• Tested compilation of all packages that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review rev HEAD". Note: all changes have to be committed, also see nixpkgs-review usage
• Tested basic functionality of all binary files (usually in ./result/bin/)
• 22.11 Release Notes (or backporting 22.05 Release notes)
  • (Package updates) Added a release notes entry if the change is major or breaking
  • (Module updates) Added a release notes entry if the change is significant
  • (Module addition) Added a release notes entry if adding a new NixOS module
  • (Release notes changes) Ran nixos/doc/manual/md-to-db.sh to update generated release notes
• Fits CONTRIBUTING.md.

[flokli]

@K900 with #80038 in mind, this looks like we can drop the patch in the systemd derivation alltogether, and only override it via the module system in the non-initrd case?

[K900]

We can, yes. I'm not sure this is any better than shipping the patch though.

[K900]

@flokli do you know where the patch series comes from?

[flokli]

The patch series is only maintained in nixpkgs these days.

Please remove the patch, reformat/rename patches according to the comment at https://github.com/NixOS/nixpkgs/blob/master/pkgs/os-specific/linux/systemd/default.nix#L150-L153, and then open a new PR, targeting staging, linking to it from here.

[K900]

Maybe we should have a NixOS/systemd fork then?

[arianvp]

We used to have a systemd fork but we moved away from and moved to patch sets to make our life as maintainers slightly easier as we have been on a multi-year effort to drop or upstream as many patches as possible. We want to run systemd as vanilla as possible as it lowers maintenance burden for us.

And the fact that we can remove this patch again signals this is the better choice from a maintenance perspective :)

[K900]

Let's continue in #182436.