diff --git a/conftest.py b/conftest.py
index 81d143eb7a..f14d595f78 100644
--- a/conftest.py
+++ b/conftest.py
@@ -174,8 +174,7 @@ def parallel(item, m):
     testname = get_testname(item)
     # Only spew tracebacks on rank 0.
     # Run xfailing tests to ensure that errors are reported to calling process
-    args = ["-n", "1", pyversion, "-m", "pytest", "--no-summary", "-s",
-            "--runxfail", "-qq", testname]
+    args = ["-n", "1", pyversion, "-m", "pytest", "-s", "--runxfail", "-qq", testname]
     if nprocs > 1:
         args.extend([":", "-n", "%d" % (nprocs - 1), pyversion, "-m", "pytest",
                      "-s", "--runxfail", "--tb=no", "-qq", "--no-summary", testname])
@@ -203,7 +202,8 @@ def decoupler(item, m):
     testname = get_testname(item)
 
     pyversion = sys.executable
-    call = [pyversion, "-m", "pytest", "--no-summary", "-s", "--runxfail", testname]
+    args = ["-n", "1", pyversion, "-m", "pytest", "-s", "--runxfail", testname]
+    call = [mpi_exec] + args
 
     return set_run_reset(env_vars, call)
 
diff --git a/devito/arch/archinfo.py b/devito/arch/archinfo.py
index ce17ecfc13..db1b329ed3 100644
--- a/devito/arch/archinfo.py
+++ b/devito/arch/archinfo.py
@@ -804,9 +804,13 @@ def _mro(cls):
     def march(self):
         return None
 
-    @property
+    @cached_property
     def numa_domains(self):
-        raise NotImplementedError
+        info = get_gpu_info()
+        try:
+            return info['ncards']
+        except KeyError:
+            return None
 
     @cached_property
     def memtotal(self):
diff --git a/tests/test_pickle.py b/tests/test_pickle.py
index 68d593e058..9b7a639a32 100644
--- a/tests/test_pickle.py
+++ b/tests/test_pickle.py
@@ -476,6 +476,29 @@ def test_receiver(self, pickle):
         assert np.all(new_rec.coordinates.data == [[0.], [1.], [2.]])
 
 
+class TestAdvanced:
+
+    def test_foreign(self):
+        MySparseFunction = type('MySparseFunction', (SparseFunction,), {'attr': 42})
+
+        grid = Grid(shape=(3,))
+
+        msf = MySparseFunction(name='msf', grid=grid, npoint=3, space_order=2,
+                               coordinates=[(0.,), (1.,), (2.,)])
+
+        # Plain `pickle` doesn't support pickling of dynamic classes
+        with pytest.raises(Exception):
+            pickle0.dumps(msf)
+
+        # But `cloudpickle` does
+        pkl_msf = pickle1.dumps(msf)
+        new_msf = pickle1.loads(pkl_msf)
+
+        assert new_msf.attr == 42
+        assert new_msf.name == 'msf'
+        assert new_msf.npoint == 3
+
+
 @pytest.mark.parametrize('pickle', [pickle0, pickle1])
 class TestOperator: