use offline-disutils in buildPythonPackage

pkgs/development/python-modules/generic/builder.sh

@@ -0,0 +1,10 @@
+source $stdenv/setup
+
+# do not allow distutils to make downloads, whatever install command is used
+export PYTHONPATH="${setuptools}/lib/${python.libPrefix}:$PYTHONPATH"
+export PYTHONPATH="${offlineDistutils}/lib/${python.libPrefix}:$PYTHONPATH"
+
+# enable pth files for dependencies
+export PYTHONPATH="${site}/lib/${python.libPrefix}/site-packages:$PYTHONPATH"
+
+genericBuild

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

@@ -3,7 +3,7 @@
    (http://pypi.python.org/pypi/setuptools/), which represents a large
    number of Python packages nowadays.  */
 
-{ python, setuptools, wrapPython, lib }:
+{ python, setuptools, wrapPython, lib, offlineDistutils }:
 
 { name, namePrefix ? "python-"
 
@@ -45,6 +45,8 @@ python.stdenv.mkDerivation (attrs // {
 
   buildInputs = [ python wrapPython setuptools ] ++ buildInputs ++ pythonPath;
 
+  builder = ./builder.sh
+
   pythonPath = [ setuptools] ++ pythonPath;
 
   # XXX: Should we run `easy_install --always-unzip'?  It doesn't seem