python310Packages.datatable: mark broken

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

@@ -61,5 +61,8 @@ buildPythonPackage rec {
     homepage = "https://github.com/h2oai/datatable";
     license = licenses.mpl20;
     maintainers = with maintainers; [ abbradar ];
+    # uses custom build system and adds -Wunused-variable -Werror
+    # warning: ‘dt::expr::doc_first’ defined but not used [-Wunused-variable]
+    broken = true;
   };
 }