Use Determinate Nix as `nix.package` for systems, homes and the
devshell, for its parallel evaluation and lazy trees. We only take the
package, not `determinate-nixd`: the daemon and `nix.conf` model are
unchanged and the Determinate NixOS module is not imported.
- Add the `determinate-nix` (`nix-src`) input, following our
`nixpkgs-unstable`. FlakeHub's cache needs auth, so we build it
ourselves and let it flow through Harmonia like everything else.
- `determinateOverlay` exposes it as `pkgs'.mine.determinate-nix`;
`lib.my.c.nix.determinateSettings` (`lazy-trees`, `eval-cores = 0`)
is merged into `nix.settings` and the devshell `nix.conf`.
- Switch CI to `DeterminateSystems/determinate-nix-action` so the
runner itself evaluates with Determinate.
- Advertise the Harmonia cache via the flake's `nixConfig`, trusted
without a prompt via `accept-flake-config` in the devshell, `.envrc`
and CI only (boxes already trust it through `nix.settings`).
- Re-attach `pkgs`/`lib` to container and installer
`nixosConfigurations` so Determinate's flake schemas can evaluate
them (`nix flake check` otherwise fails with `attribute 'pkgs'
missing`).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
jackos1998