From ca7b30470f0d8de7a2213bea09fee1102337754d Mon Sep 17 00:00:00 2001
From: Sam Willcocks <sam@wlcx.cc>
Date: Tue, 28 Feb 2023 22:02:05 +0000
Subject: [PATCH] nix: pin nixpkgs in registry to flake nixpkgs

---
 flake.nix | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/flake.nix b/flake.nix
index ddd5a74..3d68f61 100644
--- a/flake.nix
+++ b/flake.nix
@@ -53,6 +53,11 @@
                   package = pkgs.nix;
                   settings.experimental-features = "nix-command flakes";
                   settings.max-jobs = "auto"; # Gotta go fast (build derivations in parallel)
+                  # Pin the nixpkgs registry to our locked nixpkgs. This means that we
+                  # get the same packages via e.g. nix shell as we have at the system
+                  # level, so less duplication overall and no more fetching that 30MB src
+                  # every time you run nix shell.
+                  registry.nixpkgs.flake = inputs.nixpkgs;
                 };
               })
             ];