pandas: add libcxx dependency on darwin (close #9862)

vcunat changed `optional` arguments from lists to packages.

pkgs/top-level/python-packages.nix

@@ -9731,7 +9731,10 @@ let
     };
   };
 
-  pandas = buildPythonPackage rec {
+  pandas = let
+    inherit (pkgs.stdenv.lib) optional optionalString;
+    inherit (pkgs.stdenv) isDarwin;
+  in buildPythonPackage rec {
     name = "pandas-0.16.2";
 
     src = pkgs.fetchurl {
@@ -9739,7 +9742,7 @@ let
       sha256 = "10agmrkps8bi5948vwpipfxds5kj1d076m9i0nhaxwqiw7gm6670";
     };
 
-    buildInputs = [ self.nose ];
+    buildInputs = [ self.nose ] ++ optional isDarwin pkgs.libcxx;
     propagatedBuildInputs = with self; [
       dateutil
       numpy
@@ -9753,7 +9756,17 @@ let
       html5lib
       modules.sqlite3
       beautifulsoup4
-    ];
+    ] ++ optional isDarwin pkgs.darwin.adv_cmds; # provides the locale command
+
+    # For OSX, we need to add a dependency on libcxx, which provides
+    # `complex.h` and other libraries that pandas depends on to build.
+    patchPhase = optionalString isDarwin ''
+      cpp_sdk="${pkgs.libcxx}/include/c++/v1";
+      echo "Adding $cpp_sdk to the setup.py common_include variable"
+      substituteInPlace setup.py \
+        --replace "['pandas/src/klib', 'pandas/src']" \
+                  "['pandas/src/klib', 'pandas/src', '$cpp_sdk']"
+    '';
 
     preCheck = ''
       # Broken test, probably https://github.com/pydata/pandas/issues/10312: