I'm now trying to keep a branch active with the latest #NixOnWindows. I've got a demo here, which starts a tiny Windows VM with a cross-compiled Nix installed, from Linux: https://github.com/nix-windows/nix-windows-demo

Nix's CI now runs a few basic unit tests on Wine, ensuring progress to #NixOnWindows is not regressed! https://github.com/NixOS/nix/blob/ee955b3206ee3ef6e811a4960c2c15e5f1b5d09d/ci/gha/tests/windows.nix

I stayed back after work with two other people at Obsidian Systems to continue work on #NixOnWindows. It's so close to being useful! Most unit tests passing, I've even managed to do a few actual builds!

Build took a long time, since there's no binary cache yet, but I was able to build a Nix stdenv and hello.exe on Windows, thanks to the recent Cygwin-based #NixOnWindows work!

Got #NixOnWindows to pass its first functional test, executed using Wine.

Debugging #NixOnWindows using #NixOS. I'm running w64devkit's gdbserver.exe binary under wine, loading in nix.exe then connecting "remotely" to that GDB session from VSCode. I'm even loading in libstdc++'s pretty-printing, which is something I didn't have when debugging natively under Windows.

nix.exe resolving the flake registry, downloading nixpkgs, then trying to evaluate the non-existent Windows packages #NixOnWindows

First file created in the Windows Nix store #NixOnWindows

Hacked up nix.exe to start making a local store #NixOnWindows

Nix' functional test suite, running on Windows! https://github.com/nix-windows/nix/actions/runs/11695796213/job/32571822806#step:10:2751 (they all fail) #NixOnWindows