From 8ceec64be09fb0ec3530e52a5a9c35b14ce76377 Mon Sep 17 00:00:00 2001
From: Alexander Bantyev <balsoft@balsoft.ru>
Date: Thu, 3 Jun 2021 22:37:14 +0300
Subject: [PATCH] Use overlaid pkgs on old nix

---
 compat/default.nix | 1 +
 default.nix        | 9 +++++++++
 modules/nix.nix    | 3 ++-
 3 files changed, 12 insertions(+), 1 deletion(-)
 create mode 100644 compat/default.nix
 create mode 100644 default.nix

diff --git a/compat/default.nix b/compat/default.nix
new file mode 100644
index 0000000..9f77e85
--- /dev/null
+++ b/compat/default.nix
@@ -0,0 +1 @@
+{ ... }: (builtins.getFlake (toString ../.)).legacyPackages.${builtins.currentSystem}
diff --git a/default.nix b/default.nix
new file mode 100644
index 0000000..95f7513
--- /dev/null
+++ b/default.nix
@@ -0,0 +1,9 @@
+{ ... }:
+let
+  self = (import (let lock = builtins.fromJSON (builtins.readFile ./flake.lock);
+  in fetchTarball {
+    url =
+      "https://github.com/edolstra/flake-compat/archive/${lock.nodes.flake-compat.locked.rev}.tar.gz";
+    sha256 = lock.nodes.flake-compat.locked.narHash;
+  }) { src = ./.; }).defaultNix;
+in self // self.legacyPackages.${builtins.currentSystem}
diff --git a/modules/nix.nix b/modules/nix.nix
index f1b4330..408a7e2 100644
--- a/modules/nix.nix
+++ b/modules/nix.nix
@@ -1,6 +1,6 @@
 { lib, inputs, ... }: {
   nix = rec {
-    nixPath = lib.mkForce [ "nixpkgs=/etc/nixpkgs" ];
+    nixPath = lib.mkForce [ "nixpkgs=/etc/self/compat" ];
     binaryCaches = [ "https://cache.nixos.org" ];
 
     registry.self.flake = inputs.self;
@@ -23,4 +23,5 @@
     requireSignedBinaryCaches = true;
   };
   environment.etc.nixpkgs.source = inputs.nixpkgs;
+  environment.etc.self.source = inputs.self;
 }