nix: remove patch for default unstable features

hosts/default.nix

@@ -13,6 +13,13 @@ let
 
   suites = import ../suites { inherit lib; };
 
+  experimentalFeatures = [
+    "flakes"
+    "nix-command"
+    "ca-references"
+    "ca-derivations"
+  ];
+
   modules = {
     core = ../profiles/core;
     modOverrides = { config, overrideModulesPath, ... }:
@@ -47,6 +54,12 @@ let
         override.flake = override;
       };
 
+      nix.extraOptions = ''
+        experimental-features = ${lib.concatStringsSep " "
+          experimentalFeatures
+        }
+      '';
+
       system.configurationRevision = lib.mkIf (self ? rev) self.rev;
     };
 

overlays/nixFlakes.nix

@@ -1,12 +0,0 @@
-final: prev: {
-  nixFlakes = final.nix.overrideAttrs
-    (self:
-      let
-        oldPatches = self.patches or [ ];
-      in
-      {
-        patches = oldPatches ++ [
-          ../pkgs/tools/package-management/nix/0001-nix-command-and-flakes-by-default.patch
-        ];
-      });
-}

pkgs/tools/package-management/nix/0001-nix-command-and-flakes-by-default.patch

@@ -1,28 +0,0 @@
-From a47bbae869ff35095eb2fe4d4d5145054ea81049 Mon Sep 17 00:00:00 2001
-From: Timothy DeHerrera <tim.deh@pm.me>
-Date: Wed, 17 Feb 2021 12:26:48 -0700
-Subject: [PATCH] nix-command and flakes by default
-
----
- src/libstore/globals.hh | 5 ++++-
- 1 file changed, 4 insertions(+), 1 deletion(-)
-
-diff --git a/src/libstore/globals.hh b/src/libstore/globals.hh
-index eabd83e3f..e851e2a79 100644
---- a/src/libstore/globals.hh
-+++ b/src/libstore/globals.hh
-@@ -889,7 +889,10 @@ public:
-           value.
-           )"};
-
--    Setting<Strings> experimentalFeatures{this, {}, "experimental-features",
-+    Setting<Strings> experimentalFeatures{
-+        this,
-+        {"nix-command", "flakes", "ca-references"},
-+        "experimental-features",
-         "Experimental Nix features to enable."};
-
-     bool isExperimentalFeatureEnabled(const std::string & name);
---
-2.28.0
-

shell/default.nix

@@ -22,7 +22,6 @@ pkgs.devshell.mkShell
     nixos-install
     nixos-generate-config
     nixos-enter
-    pkgs.nixFlakes
   ];
 
   git.hooks = {
@@ -30,8 +29,13 @@ pkgs.devshell.mkShell
   };
 
   commands = with pkgs; [
+    { package = flk; }
     {
-      package = flk;
+      name = "nix";
+      help = pkgs.nixFlakes.meta.description;
+      command = ''
+        ${pkgs.nixFlakes}/bin/nix --experimental-features "nix-command flakes ca-references" "${"\${@}"}"
+      '';
     }
   ]
   ++ lib.optional (system != "i686-linux") { package = cachix; }