Add exception for system rebuild with copied configuration.

options/copySysConf.nix

@@ -4,17 +4,17 @@ with lib;
 
 let
   cfg = config.system.copySysConf;
-  copySysConf = pkgs.stdenv.mkDerivation rec {
-    srcPath = ../.;
+  cfgPath = ../.;
+  copySysConf = if (cfgPath == /etc/nixos) then pkgs.stdenv.mkDerivation rec {
     name = "NixOS_Configuration-${version}";
-    version = commitIdFromGitRepo (srcPath + "/.git");
+    version = commitIdFromGitRepo (cfgPath + "/.git");
 
-    src = cleanSource srcPath;
+    src = cleanSource cfgPath;
 
     installPhase = ''
       cp -R ./. $out
     '';
-  };
+  } else ../.;
 
 in {
   options.system.copySysConf = {
@@ -33,8 +33,6 @@ in {
   };
 
   config = mkIf cfg.enable {
-    # probably don't need to add it to systemPackages
-    environment.systemPackages = [ copySysConf ];
     nix = mkIf cfg.addToNixPath {
       # Do not use lib.optionals as it would override the default nixPath
       nixPath = [