gup: simplify build expression

pkgs/development/tools/build-managers/gup/build.nix

···
-# NOTE: this file is copied from the upstream repository for this package.
-# Please submit any changes you make here to https://github.com/timbertson/gup/
-
-{ stdenv, lib, python, which, pychecker ? null }:
-{ src, version, meta ? {} }:
-stdenv.mkDerivation {
-  inherit src meta;
-  name = "gup-${version}";
-  buildInputs = lib.remove null [ python which pychecker ];
-  SKIP_PYCHECKER = pychecker == null;
-  buildPhase = "make python";
-  installPhase = ''
-    mkdir $out
-    cp -r python/bin $out/bin
-  '';
-}

pkgs/development/tools/build-managers/gup/default.nix

···
-{ stdenv, fetchFromGitHub, lib, python, which }:
-let
+{ stdenv, fetchFromGitHub, lib, python, which, pychecker ? null }:
+stdenv.mkDerivation rec {
   version = "0.7.0";
   src = fetchFromGitHub {
     sha256 = "1pwnmlq2pgkkln9sgz4wlb9dqlqw83bkf105qljnlvggc21zm3pv";
···
     repo = "gup";
     owner = "timbertson";
   };
-in
-import ./build.nix
-  { inherit stdenv lib python which; }
-  { inherit src version;
-    meta = {
-      inherit (src.meta) homepage;
-      description = "A better make, inspired by djb's redo";
-      license = stdenv.lib.licenses.lgpl2Plus;
-      maintainers = [ stdenv.lib.maintainers.timbertson ];
-      platforms = stdenv.lib.platforms.all;
-    };
-  }
+  name = "gup-${version}";
+  buildInputs = lib.remove null [ python which pychecker ];
+  SKIP_PYCHECKER = pychecker == null;
+  buildPhase = "make python";
+  installPhase = ''
+    mkdir $out
+    cp -r python/bin $out/bin
+  '';
+  meta = {
+    inherit (src.meta) homepage;
+    description = "A better make, inspired by djb's redo";
+    license = stdenv.lib.licenses.lgpl2Plus;
+    maintainers = [ stdenv.lib.maintainers.timbertson ];
+    platforms = stdenv.lib.platforms.all;
+  };
+}