python.pkgs.psutil: move to separate expression

pkgs/development/python-modules/psutil/default.nix

@@ -0,0 +1,28 @@
+{ stdenv
+, buildPythonPackage
+, fetchPypi
+, darwin
+, mock
+}:
+
+buildPythonPackage rec {
+  pname = "psutil";
+  version = "4.3.0";
+  name = "${pname}-${version}";
+
+  src = fetchPypi {
+    inherit pname version;
+    sha256 = "1w4r09fvn6kd80m5mx4ws1wz100brkaq6hzzpwrns8cgjzjpl6c6";
+  };
+
+  # No tests in archive
+  doCheck = false;
+
+  buildInputs = [] ++ stdenv.lib.optionals stdenv.isDarwin [ darwin.IOKit ];
+
+  meta = {
+    description = "Process and system utilization information interface for python";
+    homepage = https://github.com/giampaolo/psutil;
+    license = stdenv.lib.licenses.bsd3;
+  };
+}

pkgs/top-level/python-packages.nix

@@ -14878,31 +14878,13 @@ in {
 
   psd-tools = callPackage ../development/python-modules/psd-tools { };
 
-  psutil = buildPythonPackage rec {
-    name = "psutil-${version}";
-    version = "4.3.0";
+  psutil = callPackage ../development/python-modules/psutil { };
 
-    src = pkgs.fetchurl {
-      url = "mirror://pypi/p/psutil/${name}.tar.gz";
-      sha256 = "1w4r09fvn6kd80m5mx4ws1wz100brkaq6hzzpwrns8cgjzjpl6c6";
-    };
-
-    # Certain tests fail due to being in a chroot.
-    # See also the older issue: https://code.google.com/p/psutil/issues/detail?id=434
-    doCheck = false;
-
-    buildInputs = with self; [ mock ] ++ optionals stdenv.isDarwin [ pkgs.darwin.IOKit ];
-
-    meta = {
-      description = "Process and system utilization information interface for python";
-      homepage = https://github.com/giampaolo/psutil;
-    };
-  };
-
-  psutil_1 = self.psutil.overrideDerivation (self: rec {
-    name = "psutil-1.2.1";
-    src = pkgs.fetchurl {
-      url = "mirror://pypi/p/psutil/${name}.tar.gz";
+  psutil_1 = self.psutil.overrideAttrs (oldAttrs: rec {
+    name = "${oldAttrs.pname}-${version}";
+    version = "1.2.1";
+    src = oldAttrs.src.override {
+      inherit version;
       sha256 = "0ibclqy6a4qmkjhlk3g8jhpvnk0v9aywknc61xm3hfi5r124m3jh";
     };
   });