From f151954d1410046ee3876fd9b33b06c9261fa3d6 Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <edolstra@gmail.com>
Date: Mon, 17 Jun 2024 16:59:19 +0200
Subject: [PATCH] Allow the 'nix' input to point to the Nix repo (#1013)

This way, you can build upstream Nix or a branch/fork by doing

  nix build --override-input github:my-org/nix/my-branch

without needing the https://github.com/DeterminateSystems/nix wrapper.
---
 flake.nix | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/flake.nix b/flake.nix
index 2810c06a2..eff3f58a5 100644
--- a/flake.nix
+++ b/flake.nix
@@ -55,6 +55,10 @@
         ] ++ nixpkgs.lib.optionals (system == "aarch64-linux") [
           targets.aarch64-unknown-linux-musl.stable.rust-std
         ]);
+
+      nixTarballs = forAllSystems ({ system, ... }:
+        inputs.nix.tarballs_direct.${system}
+          or "${inputs.nix.checks."${system}".binaryTarball}/nix-${inputs.nix.packages."${system}".default.version}-${system}.tar.xz");
     in
     {
       overlays.default = final: prev:
@@ -87,7 +91,7 @@
             RUSTFLAGS = "--cfg tokio_unstable";
             cargoTestOptions = f: f ++ [ "--all" ];
 
-            NIX_INSTALLER_TARBALL_PATH = inputs.nix.tarballs_direct.${final.stdenv.system};
+            NIX_INSTALLER_TARBALL_PATH = nixTarballs.${final.stdenv.system};
 
             override = { preBuild ? "", ... }: {
               preBuild = preBuild + ''
@@ -132,7 +136,7 @@
             name = "nix-install-shell";
 
             RUST_SRC_PATH = "${toolchain}/lib/rustlib/src/rust/library";
-            NIX_INSTALLER_TARBALL_PATH = inputs.nix.tarballs_direct.${system};
+            NIX_INSTALLER_TARBALL_PATH = nixTarballs.${system};
 
             nativeBuildInputs = with pkgs; [ ];
             buildInputs = with pkgs; [