python3Packages.datatable: get libc++ headers on Darwin from stdenv.cc.libcxx

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

@@ -6,7 +6,6 @@
   pipInstallHook,
   blessed,
   docutils,
-  libcxx,
   llvm,
   pytestCheckHook,
   typesentry,
@@ -53,7 +52,7 @@ buildPythonPackage rec {
   ];
 
   LLVM = llvm;
-  env.NIX_CFLAGS_COMPILE = lib.optionalString stdenv.hostPlatform.isDarwin "-isystem ${lib.getDev libcxx}/include/c++/v1";
+  env.NIX_CFLAGS_COMPILE = lib.optionalString stdenv.hostPlatform.isDarwin "-isystem ${lib.getInclude stdenv.cc.libcxx}/include/c++/v1";
 
   # test suite is very cpu intensive, only run small subset to ensure package is working as expected
   pytestFlagsArray = [ "tests/test-sets.py" ];