I was seeing a stack trace with this at the bottom:
error: cannot look up '<home-manager/nixos>' in pure evaluation mode (use '--impure' to override)
After reading a bit at https://nixos-and-flakes.thiscute.world/nixos-with-flakes/start-using-home-manager
I was able to craft this shape which uses home-manager in a flake and
doesn't have the same problem.
This also changes to directly referencing the local git checkout of my
flake definition which makes it faster and safer to iterate on the
logic.
At this point I am creating a systemd unit file, but it's not correct at
all.
Eli Ribble