I believe the error comes from this line: nixpkgs/pkgs/by-name/ni/nixos-install/nixos-install.sh at 36864ed72f234b9540da4cf7a0c49e351d30d3f1 · NixOS/nixpkgs · GitHub
Notice how it’s line 8 of the snippet, which aligns with the error messages reported here.
(it’s line 10 in nixos-unstable, line 8 in 24.11)
I think the fix is to have the target’s util-linux on PATH (which may differ from the util-linux installed on your host). The easy way to do this would be to just have the target’s system-path on PATH. So add /nix/var/nix/profiles/system/sw/bin to PATH, and I think that will fix it.