python: add python.interpreter attribute

pkgs/development/interpreters/pypy/2.4/default.nix

@@ -95,11 +95,12 @@ let
          --set LIBRARY_PATH "${LIBRARY_PATH}"
     '';
 
-    passthru = {
+    passthru = rec {
       inherit zlibSupport libPrefix;
       executable = "pypy";
       isPypy = true;
       buildEnv = callPackage ../../python/wrapper.nix { python = self; };
+      interpreter = "${self}/bin/${executable}";
     };
 
     enableParallelBuilding = true;

pkgs/development/interpreters/python/2.6/default.nix

@@ -93,6 +93,7 @@ let
       libPrefix = "python${majorVersion}";
       executable = libPrefix;
       sitePackages = "lib/${libPrefix}/site-packages";
+      interpreter = "${self}/bin/${executable}";
     };
 
     enableParallelBuilding = true;

pkgs/development/interpreters/python/2.7/default.nix

@@ -100,6 +100,7 @@ let
       libPrefix = "python${majorVersion}";
       executable = libPrefix;
       sitePackages = "lib/${libPrefix}/site-packages";
+      interpreter = "${self}/bin/${executable}";
     };
 
     enableParallelBuilding = true;

pkgs/development/interpreters/python/3.2/default.nix

@@ -80,6 +80,7 @@ stdenv.mkDerivation {
     isPy32 = true;
     is_py3k = true;  # deprecated
     sitePackages = "lib/${libPrefix}/site-packages";
+    interpreter = "${self}/bin/${executable}";
   };
 
   enableParallelBuilding = true;

pkgs/development/interpreters/python/3.3/default.nix

@@ -81,6 +81,7 @@ stdenv.mkDerivation {
     isPy33 = true;
     is_py3k = true;  # deprecated
     sitePackages = "lib/${libPrefix}/site-packages";
+    interpreter = "${self}/bin/${executable}";
   };
 
   enableParallelBuilding = true;

pkgs/development/interpreters/python/3.4/default.nix

@@ -83,6 +83,7 @@ stdenv.mkDerivation {
     isPy34 = true;
     is_py3k = true;  # deprecated
     sitePackages = "lib/${libPrefix}/site-packages";
+    interpreter = "${self}/bin/${executable}";
   };
 
   enableParallelBuilding = true;