Add nix-exec package

pkgs/development/interpreters/nix-exec/default.nix

@@ -0,0 +1,23 @@
+{ stdenv, fetchurl, pkgconfig, nix }: let
+  version = "1.0.0";
+in stdenv.mkDerivation {
+  name = "nix-exec-${version}";
+
+  src = fetchurl {
+    url = "https://github.com/shlevy/nix-exec/releases/download/v${version}/nix-exec-${version}.tar.xz";
+
+    sha256 = "0w89ma69iil1ki68zvs1l0ii0d87in64791l3a4yzyv9d3ncl3w6";
+  };
+
+  buildInputs = [ pkgconfig nix ];
+
+  meta = {
+    description = "Run programs defined in nix expressions";
+
+    homepage = https://github.com/shlevy/nix-exec;
+
+    license = stdenv.lib.licenses.mit;
+
+    maintainers = [ stdenv.lib.maintainers.shlevy ];
+  };
+}

pkgs/top-level/all-packages.nix

@@ -3802,6 +3802,10 @@ let
     pythonProtobuf = pythonPackages.protobuf;
   };
 
+  nix-exec = callPackage ../development/interpreters/nix-exec {
+    nix = nixUnstable;
+  };
+
   octave = callPackage ../development/interpreters/octave {
     fltk = fltk13;
     qt = null;