Add gurobipy for python2.7 on darwin.

pkgs/development/python-modules/gurobipy/darwin.nix

@@ -0,0 +1,34 @@
+{ stdenv, fetchurl, python, xar, cpio, cctools, insert_dylib }:
+assert python.isPy27 && python.ucsEncoding == 2;
+stdenv.mkDerivation
+  { name = "gurobipy-7.0.2";
+    src = fetchurl
+      { url = "http://packages.gurobi.com/7.0/gurobi7.0.2_mac64.pkg";
+        sha256 = "14dpxas6gx02kfb28i0fh68p1z4sbjmwg8hp8h5ch6c701h260mg";
+      };
+    buildInputs = [ xar cpio cctools insert_dylib ];
+    buildCommand =
+      ''
+        # Unpack
+        xar -xf $src
+        zcat gurobi*mac64tar.pkg/Payload | cpio -i
+        tar xf gurobi*_mac64.tar.gz
+
+        # Install
+        cd gurobi*/mac64
+        mkdir -p $out/lib/python2.7/site-packages
+        mv lib/python2.7/gurobipy $out/lib/python2.7/site-packages
+        mv lib/lib*.so $out/lib
+
+        # Fixup
+        install_name_tool -change \
+          /System/Library/Frameworks/Python.framework/Versions/2.7/Python \
+          ${python}/lib/libpython2.7.dylib \
+          $out/lib/python2.7/site-packages/gurobipy/gurobipy.so
+        install_name_tool -change libgurobi70.so \
+          $out/lib/libgurobi70.so \
+          $out/lib/python2.7/site-packages/gurobipy/gurobipy.so
+        insert_dylib --inplace $out/lib/libaes70.so \
+          $out/lib/python2.7/site-packages/gurobipy/gurobipy.so
+      '';
+  }