nix-daemon.nix: Add option nix.registry

This allows you to specify the system-wide flake registry. One use is
to pin 'nixpkgs' to the Nixpkgs version used to build the system:

  nix.registry.nixpkgs.flake = nixpkgs;

where 'nixpkgs' is a flake input. This ensures that commands like

  $ nix run nixpkgs#hello

pull in a minimum of additional store paths.

You can also use this to redirect flakes, e.g.

  nix.registry.nixpkgs.to = {
    type = "github";
    owner = "my-org";
    repo = "my-nixpkgs";
  };

1 files changed, 1 insertions, 1 deletions

diff --git a/pkgs/top-level/make-tarball.nix b/pkgs/top-level/make-tarball.nix
index bb0d7bc54e78..6bb243879e9a 100644
--- a/pkgs/top-level/make-tarball.nix
+++ b/pkgs/top-level/make-tarball.nix
@@ -19,7 +19,7 @@ releaseTools.sourceTarball {
   version = pkgs.lib.fileContents ../../.version;
   versionSuffix = "pre${
     if nixpkgs ? lastModified
-    then builtins.substring 0 8 nixpkgs.lastModified
+    then builtins.substring 0 8 (nixpkgs.lastModifiedDate or nixpkgs.lastModified)
     else toString nixpkgs.revCount}.${nixpkgs.shortRev or "dirty"}";
 
   buildInputs = [ nix.out jq lib-tests pkgs.brotli ];