slightly clearer code for running the tagged unittests

Author: timfel

mx.graalpython/mx_graalpython.py

@@ -404,13 +404,17 @@ def graalpython_gate_runner(args, tasks):
 
     with Task('GraalPython Python tests', tasks, tags=[GraalPythonTags.tagged]) as task:
         if task:
-            with set_env(ENABLE_CPYTHON_TAGGED_UNITTESTS="true", ENABLE_THREADED_GRAALPYTEST="true", GRAAL_PYTHONHOME=_dev_pythonhome()):
+            with set_env(ENABLE_CPYTHON_TAGGED_UNITTESTS="true", ENABLE_THREADED_GRAALPYTEST="true"):
                 # the tagged unittests must ron in the dev_pythonhome and using
                 # the dev CAPI, because that's where the tags are
-                run_python_unittests(python_gvm(),
-                                     args=["--python.WithThread=true",
-                                           "--python.CAPI=" + mx.dependency("com.oracle.graal.python.cext").get_output_root()],
-                                     paths=["test_tagged_unittests.py"])
+                with _dev_pythonhome_context():
+                    run_python_unittests(
+                        python_gvm(),
+                        args=["-v",
+                              "--python.WithThread=true",
+                              "--python.CAPI=" + mx.dependency("com.oracle.graal.python.cext").get_output_root()],
+                        paths=["test_tagged_unittests.py"]
+                    )
 
     # Unittests on SVM
     with Task('GraalPython tests on SVM', tasks, tags=[GraalPythonTags.svmunit]) as task: