python3Packages.datatable: reduce test suite to small subset

test suite is very cpu intensive

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

@@ -44,15 +44,9 @@ buildPythonPackage rec {
   LLVM = llvm;
   NIX_CFLAGS_COMPILE = lib.optionalString stdenv.isDarwin "-isystem ${lib.getDev libcxx}/include/c++/v1";
 
-  pytestFlagsArray = let
-    # ini file (not included in tarball) required to change python_files setting,
-    pytestIni = writeText "pytest.ini" ''
-      [pytest]
-      python_files = test_*.py test-*.py
-    '';
-  in [
-    "-c ${pytestIni}"
-  ];
+  # test suite is very cpu intensive, only run small subset to ensure package is working as expected
+  pytestFlagsArray = [ "tests/test-sets.py" ];
+
   disabledTests = [
     # skip tests which are irrelevant to our installation or use way too much memory
     "test_xfunction_paths"