From 761bb1137445c75c4ba87d3669dd546e25277cd5 Mon Sep 17 00:00:00 2001 From: Nick Coghlan Date: Sat, 14 Jul 2012 23:59:22 +1000 Subject: [PATCH] Close #15230: runpy.run_path now sets __package__ correctly. Also refactored the runpy tests to use a more systematic approach --- Lib/runpy.py | 6 +- Lib/test/test_runpy.py | 422 ++++++++++++++++++++++++++--------------- Misc/NEWS | 5 + 3 files changed, 276 insertions(+), 157 deletions(-) diff --git a/Lib/runpy.py b/Lib/runpy.py index 31e5e55cfa0..7cb4668a01c 100644 --- a/Lib/runpy.py +++ b/Lib/runpy.py @@ -68,6 +68,7 @@ def _run_code(code, run_globals, init_globals=None, run_globals.update(__name__ = mod_name, __file__ = mod_fname, __cached__ = None, + __doc__ = None, __loader__ = mod_loader, __package__ = pkg_name) exec(code, run_globals) @@ -242,12 +243,14 @@ def run_path(path_name, init_globals=None, run_name=None): """ if run_name is None: run_name = "" + pkg_name = run_name.rpartition(".")[0] importer = _get_importer(path_name) if isinstance(importer, imp.NullImporter): # Not a valid sys.path entry, so run the code directly # execfile() doesn't help as we want to allow compiled files code = _get_code_from_file(path_name) - return _run_module_code(code, init_globals, run_name, path_name) + return _run_module_code(code, init_globals, run_name, path_name, + pkg_name=pkg_name) else: # Importer is defined for path, so add it to # the start of sys.path @@ -266,7 +269,6 @@ def run_path(path_name, init_globals=None, run_name=None): mod_name, loader, code, fname = _get_main_module_details() finally: sys.modules[main_name] = saved_main - pkg_name = "" with _TempModule(run_name) as temp_module, \ _ModifiedArgv0(path_name): mod_globals = temp_module.module.__dict__ diff --git a/Lib/test/test_runpy.py b/Lib/test/test_runpy.py index 7ffb6af6341..85eb76fa79f 100644 --- a/Lib/test/test_runpy.py +++ b/Lib/test/test_runpy.py @@ -10,80 +10,143 @@ from test.support import forget, make_legacy_pyc, run_unittest, unload, verbose from test.script_helper import ( make_pkg, make_script, make_zip_pkg, make_zip_script, temp_dir) - +import runpy from runpy import _run_code, _run_module_code, run_module, run_path # Note: This module can't safely test _run_module_as_main as it # runs its tests in the current process, which would mess with the # real __main__ module (usually test.regrtest) # See test_cmd_line_script for a test that executes that code path -# Set up the test code and expected results -class RunModuleCodeTest(unittest.TestCase): +# Set up the test code and expected results +example_source = """\ +# Check basic code execution +result = ['Top level assignment'] +def f(): + result.append('Lower level reference') +f() +del f +# Check the sys module +import sys +run_argv0 = sys.argv[0] +run_name_in_sys_modules = __name__ in sys.modules +module_in_sys_modules = (run_name_in_sys_modules and + globals() is sys.modules[__name__].__dict__) +# Check nested operation +import runpy +nested = runpy._run_module_code('x=1\\n', mod_name='') +""" + +implicit_namespace = { + "__name__": None, + "__file__": None, + "__cached__": None, + "__package__": None, + "__doc__": None, +} +example_namespace = { + "sys": sys, + "runpy": runpy, + "result": ["Top level assignment", "Lower level reference"], + "run_argv0": sys.argv[0], + "run_name_in_sys_modules": False, + "module_in_sys_modules": False, + "nested": dict(implicit_namespace, + x=1, __name__="", __loader__=None), +} +example_namespace.update(implicit_namespace) + +class CodeExecutionMixin: + # Issue #15230 (run_path not handling run_name correctly) highlighted a + # problem with the way arguments were being passed from higher level APIs + # down to lower level code. This mixin makes it easier to ensure full + # testing occurs at those upper layers as well, not just at the utility + # layer + + def assertNamespaceMatches(self, result_ns, expected_ns): + """Check two namespaces match. + + Ignores any unspecified interpreter created names + """ + # Impls are permitted to add extra names, so filter them out + for k in list(result_ns): + if k.startswith("__") and k.endswith("__"): + if k not in expected_ns: + result_ns.pop(k) + if k not in expected_ns["nested"]: + result_ns["nested"].pop(k) + # Don't use direct dict comparison - the diffs are too hard to debug + self.assertEqual(set(result_ns), set(expected_ns)) + for k in result_ns: + actual = (k, result_ns[k]) + expected = (k, expected_ns[k]) + self.assertEqual(actual, expected) + + def check_code_execution(self, create_namespace, expected_namespace): + """Check that an interface runs the example code correctly + + First argument is a callable accepting the initial globals and + using them to create the actual namespace + Second argument is the expected result + """ + sentinel = object() + expected_ns = expected_namespace.copy() + run_name = expected_ns["__name__"] + saved_argv0 = sys.argv[0] + saved_mod = sys.modules.get(run_name, sentinel) + # Check without initial globals + result_ns = create_namespace(None) + self.assertNamespaceMatches(result_ns, expected_ns) + self.assertIs(sys.argv[0], saved_argv0) + self.assertIs(sys.modules.get(run_name, sentinel), saved_mod) + # And then with initial globals + initial_ns = {"sentinel": sentinel} + expected_ns["sentinel"] = sentinel + result_ns = create_namespace(initial_ns) + self.assertIsNot(result_ns, initial_ns) + self.assertNamespaceMatches(result_ns, expected_ns) + self.assertIs(sys.argv[0], saved_argv0) + self.assertIs(sys.modules.get(run_name, sentinel), saved_mod) + + +class ExecutionLayerTestCase(unittest.TestCase, CodeExecutionMixin): """Unit tests for runpy._run_code and runpy._run_module_code""" - expected_result = ["Top level assignment", "Lower level reference"] - test_source = ( - "# Check basic code execution\n" - "result = ['Top level assignment']\n" - "def f():\n" - " result.append('Lower level reference')\n" - "f()\n" - "# Check the sys module\n" - "import sys\n" - "run_argv0 = sys.argv[0]\n" - "run_name_in_sys_modules = __name__ in sys.modules\n" - "if run_name_in_sys_modules:\n" - " module_in_sys_modules = globals() is sys.modules[__name__].__dict__\n" - "# Check nested operation\n" - "import runpy\n" - "nested = runpy._run_module_code('x=1\\n', mod_name='')\n" - ) - def test_run_code(self): - saved_argv0 = sys.argv[0] - d = _run_code(self.test_source, {}) - self.assertEqual(d["result"], self.expected_result) - self.assertIs(d["__name__"], None) - self.assertIs(d["__file__"], None) - self.assertIs(d["__cached__"], None) - self.assertIs(d["__loader__"], None) - self.assertIs(d["__package__"], None) - self.assertIs(d["run_argv0"], saved_argv0) - self.assertNotIn("run_name", d) - self.assertIs(sys.argv[0], saved_argv0) + expected_ns = example_namespace.copy() + expected_ns.update({ + "__loader__": None, + }) + def create_ns(init_globals): + return _run_code(example_source, {}, init_globals) + self.check_code_execution(create_ns, expected_ns) def test_run_module_code(self): - initial = object() - name = "" - file = "Some other nonsense" - loader = "Now you're just being silly" - package = '' # Treat as a top level module - d1 = dict(initial=initial) - saved_argv0 = sys.argv[0] - d2 = _run_module_code(self.test_source, - d1, - name, - file, - loader, - package) - self.assertNotIn("result", d1) - self.assertIs(d2["initial"], initial) - self.assertEqual(d2["result"], self.expected_result) - self.assertEqual(d2["nested"]["x"], 1) - self.assertIs(d2["__name__"], name) - self.assertTrue(d2["run_name_in_sys_modules"]) - self.assertTrue(d2["module_in_sys_modules"]) - self.assertIs(d2["__file__"], file) - self.assertIs(d2["__cached__"], None) - self.assertIs(d2["run_argv0"], file) - self.assertIs(d2["__loader__"], loader) - self.assertIs(d2["__package__"], package) - self.assertIs(sys.argv[0], saved_argv0) - self.assertNotIn(name, sys.modules) + mod_name = "" + mod_fname = "Some other nonsense" + mod_loader = "Now you're just being silly" + mod_package = '' # Treat as a top level module + expected_ns = example_namespace.copy() + expected_ns.update({ + "__name__": mod_name, + "__file__": mod_fname, + "__loader__": mod_loader, + "__package__": mod_package, + "run_argv0": mod_fname, + "run_name_in_sys_modules": True, + "module_in_sys_modules": True, + }) + def create_ns(init_globals): + return _run_module_code(example_source, + init_globals, + mod_name, + mod_fname, + mod_loader, + mod_package) + self.check_code_execution(create_ns, expected_ns) -class RunModuleTest(unittest.TestCase): +class RunModuleTestCase(unittest.TestCase, CodeExecutionMixin): """Unit tests for runpy.run_module""" def expect_import_error(self, mod_name): @@ -107,7 +170,7 @@ class RunModuleTest(unittest.TestCase): self.expect_import_error("multiprocessing") def test_library_module(self): - run_module("runpy") + self.assertEqual(run_module("runpy")["__name__"], "runpy") def _add_pkg_dir(self, pkg_dir): os.mkdir(pkg_dir) @@ -120,19 +183,19 @@ class RunModuleTest(unittest.TestCase): pkg_name = "__runpy_pkg__" test_fname = mod_base+os.extsep+"py" pkg_dir = sub_dir = tempfile.mkdtemp() - if verbose: print(" Package tree in:", sub_dir) + if verbose > 1: print(" Package tree in:", sub_dir) sys.path.insert(0, pkg_dir) - if verbose: print(" Updated sys.path:", sys.path[0]) + if verbose > 1: print(" Updated sys.path:", sys.path[0]) for i in range(depth): sub_dir = os.path.join(sub_dir, pkg_name) pkg_fname = self._add_pkg_dir(sub_dir) - if verbose: print(" Next level in:", sub_dir) - if verbose: print(" Created:", pkg_fname) + if verbose > 1: print(" Next level in:", sub_dir) + if verbose > 1: print(" Created:", pkg_fname) mod_fname = os.path.join(sub_dir, test_fname) mod_file = open(mod_fname, "w") mod_file.write(source) mod_file.close() - if verbose: print(" Created:", mod_fname) + if verbose > 1: print(" Created:", mod_fname) mod_name = (pkg_name+".")*depth + mod_base return pkg_dir, mod_fname, mod_name @@ -140,73 +203,98 @@ class RunModuleTest(unittest.TestCase): for entry in list(sys.modules): if entry.startswith("__runpy_pkg__"): del sys.modules[entry] - if verbose: print(" Removed sys.modules entries") + if verbose > 1: print(" Removed sys.modules entries") del sys.path[0] - if verbose: print(" Removed sys.path entry") + if verbose > 1: print(" Removed sys.path entry") for root, dirs, files in os.walk(top, topdown=False): for name in files: try: os.remove(os.path.join(root, name)) except OSError as ex: - if verbose: print(ex) # Persist with cleaning up + if verbose > 1: print(ex) # Persist with cleaning up for name in dirs: fullname = os.path.join(root, name) try: os.rmdir(fullname) except OSError as ex: - if verbose: print(ex) # Persist with cleaning up + if verbose > 1: print(ex) # Persist with cleaning up try: os.rmdir(top) - if verbose: print(" Removed package tree") + if verbose > 1: print(" Removed package tree") except OSError as ex: - if verbose: print(ex) # Persist with cleaning up + if verbose > 1: print(ex) # Persist with cleaning up - def _check_module(self, depth): + def _fix_ns_for_legacy_pyc(self, ns, alter_sys): + char_to_add = "c" if __debug__ else "o" + ns["__file__"] += char_to_add + if alter_sys: + ns["run_argv0"] += char_to_add + + + def _check_module(self, depth, alter_sys=False): pkg_dir, mod_fname, mod_name = ( - self._make_pkg("x=1\n", depth)) + self._make_pkg(example_source, depth)) forget(mod_name) + expected_ns = example_namespace.copy() + expected_ns.update({ + "__name__": mod_name, + "__file__": mod_fname, + "__package__": mod_name.rpartition(".")[0], + }) + if alter_sys: + expected_ns.update({ + "run_argv0": mod_fname, + "run_name_in_sys_modules": True, + "module_in_sys_modules": True, + }) + def create_ns(init_globals): + return run_module(mod_name, init_globals, alter_sys=alter_sys) try: - if verbose: print("Running from source:", mod_name) - d1 = run_module(mod_name) # Read from source - self.assertIn("x", d1) - self.assertEqual(d1["x"], 1) - del d1 # Ensure __loader__ entry doesn't keep file open + if verbose > 1: print("Running from source:", mod_name) + self.check_code_execution(create_ns, expected_ns) __import__(mod_name) os.remove(mod_fname) make_legacy_pyc(mod_fname) unload(mod_name) # In case loader caches paths - if verbose: print("Running from compiled:", mod_name) - d2 = run_module(mod_name) # Read from bytecode - self.assertIn("x", d2) - self.assertEqual(d2["x"], 1) - del d2 # Ensure __loader__ entry doesn't keep file open + if verbose > 1: print("Running from compiled:", mod_name) + self._fix_ns_for_legacy_pyc(expected_ns, alter_sys) + self.check_code_execution(create_ns, expected_ns) finally: self._del_pkg(pkg_dir, depth, mod_name) - if verbose: print("Module executed successfully") + if verbose > 1: print("Module executed successfully") - def _check_package(self, depth): + def _check_package(self, depth, alter_sys=False): pkg_dir, mod_fname, mod_name = ( - self._make_pkg("x=1\n", depth, "__main__")) - pkg_name, _, _ = mod_name.rpartition(".") + self._make_pkg(example_source, depth, "__main__")) + pkg_name = mod_name.rpartition(".")[0] forget(mod_name) + expected_ns = example_namespace.copy() + expected_ns.update({ + "__name__": mod_name, + "__file__": mod_fname, + "__package__": pkg_name, + }) + if alter_sys: + expected_ns.update({ + "run_argv0": mod_fname, + "run_name_in_sys_modules": True, + "module_in_sys_modules": True, + }) + def create_ns(init_globals): + return run_module(pkg_name, init_globals, alter_sys=alter_sys) try: - if verbose: print("Running from source:", pkg_name) - d1 = run_module(pkg_name) # Read from source - self.assertIn("x", d1) - self.assertTrue(d1["x"] == 1) - del d1 # Ensure __loader__ entry doesn't keep file open + if verbose > 1: print("Running from source:", pkg_name) + self.check_code_execution(create_ns, expected_ns) __import__(mod_name) os.remove(mod_fname) make_legacy_pyc(mod_fname) unload(mod_name) # In case loader caches paths - if verbose: print("Running from compiled:", pkg_name) - d2 = run_module(pkg_name) # Read from bytecode - self.assertIn("x", d2) - self.assertTrue(d2["x"] == 1) - del d2 # Ensure __loader__ entry doesn't keep file open + if verbose > 1: print("Running from compiled:", pkg_name) + self._fix_ns_for_legacy_pyc(expected_ns, alter_sys) + self.check_code_execution(create_ns, expected_ns) finally: self._del_pkg(pkg_dir, depth, pkg_name) - if verbose: print("Package executed successfully") + if verbose > 1: print("Package executed successfully") def _add_relative_modules(self, base_dir, source, depth): if depth <= 1: @@ -220,18 +308,18 @@ class RunModuleTest(unittest.TestCase): sibling_fname = os.path.join(module_dir, "sibling.py") sibling_file = open(sibling_fname, "w") sibling_file.close() - if verbose: print(" Added sibling module:", sibling_fname) + if verbose > 1: print(" Added sibling module:", sibling_fname) # Add nephew module uncle_dir = os.path.join(parent_dir, "uncle") self._add_pkg_dir(uncle_dir) - if verbose: print(" Added uncle package:", uncle_dir) + if verbose > 1: print(" Added uncle package:", uncle_dir) cousin_dir = os.path.join(uncle_dir, "cousin") self._add_pkg_dir(cousin_dir) - if verbose: print(" Added cousin package:", cousin_dir) + if verbose > 1: print(" Added cousin package:", cousin_dir) nephew_fname = os.path.join(cousin_dir, "nephew.py") nephew_file = open(nephew_fname, "w") nephew_file.close() - if verbose: print(" Added nephew module:", nephew_fname) + if verbose > 1: print(" Added nephew module:", nephew_fname) def _check_relative_imports(self, depth, run_name=None): contents = r"""\ @@ -241,13 +329,17 @@ from ..uncle.cousin import nephew """ pkg_dir, mod_fname, mod_name = ( self._make_pkg(contents, depth)) + if run_name is None: + expected_name = mod_name + else: + expected_name = run_name try: self._add_relative_modules(pkg_dir, contents, depth) pkg_name = mod_name.rpartition('.')[0] - if verbose: print("Running from source:", mod_name) + if verbose > 1: print("Running from source:", mod_name) d1 = run_module(mod_name, run_name=run_name) # Read from source - self.assertIn("__package__", d1) - self.assertTrue(d1["__package__"] == pkg_name) + self.assertEqual(d1["__name__"], expected_name) + self.assertEqual(d1["__package__"], pkg_name) self.assertIn("sibling", d1) self.assertIn("nephew", d1) del d1 # Ensure __loader__ entry doesn't keep file open @@ -255,77 +347,97 @@ from ..uncle.cousin import nephew os.remove(mod_fname) make_legacy_pyc(mod_fname) unload(mod_name) # In case the loader caches paths - if verbose: print("Running from compiled:", mod_name) + if verbose > 1: print("Running from compiled:", mod_name) d2 = run_module(mod_name, run_name=run_name) # Read from bytecode - self.assertIn("__package__", d2) - self.assertTrue(d2["__package__"] == pkg_name) + self.assertEqual(d2["__name__"], expected_name) + self.assertEqual(d2["__package__"], pkg_name) self.assertIn("sibling", d2) self.assertIn("nephew", d2) del d2 # Ensure __loader__ entry doesn't keep file open finally: self._del_pkg(pkg_dir, depth, mod_name) - if verbose: print("Module executed successfully") + if verbose > 1: print("Module executed successfully") def test_run_module(self): for depth in range(4): - if verbose: print("Testing package depth:", depth) + if verbose > 1: print("Testing package depth:", depth) self._check_module(depth) def test_run_package(self): for depth in range(1, 4): - if verbose: print("Testing package depth:", depth) + if verbose > 1: print("Testing package depth:", depth) self._check_package(depth) + def test_run_module_alter_sys(self): + for depth in range(4): + if verbose > 1: print("Testing package depth:", depth) + self._check_module(depth, alter_sys=True) + + def test_run_package_alter_sys(self): + for depth in range(1, 4): + if verbose > 1: print("Testing package depth:", depth) + self._check_package(depth, alter_sys=True) + def test_explicit_relative_import(self): for depth in range(2, 5): - if verbose: print("Testing relative imports at depth:", depth) + if verbose > 1: print("Testing relative imports at depth:", depth) self._check_relative_imports(depth) def test_main_relative_import(self): for depth in range(2, 5): - if verbose: print("Testing main relative imports at depth:", depth) + if verbose > 1: print("Testing main relative imports at depth:", depth) self._check_relative_imports(depth, "__main__") + def test_run_name(self): + depth = 1 + run_name = "And now for something completely different" + pkg_dir, mod_fname, mod_name = ( + self._make_pkg(example_source, depth)) + forget(mod_name) + expected_ns = example_namespace.copy() + expected_ns.update({ + "__name__": run_name, + "__file__": mod_fname, + "__package__": mod_name.rpartition(".")[0], + }) + def create_ns(init_globals): + return run_module(mod_name, init_globals, run_name) + try: + self.check_code_execution(create_ns, expected_ns) + finally: + self._del_pkg(pkg_dir, depth, mod_name) -class RunPathTest(unittest.TestCase): + +class RunPathTestCase(unittest.TestCase, CodeExecutionMixin): """Unit tests for runpy.run_path""" - # Based on corresponding tests in test_cmd_line_script - - test_source = """\ -# Script may be run with optimisation enabled, so don't rely on assert -# statements being executed -def assertEqual(lhs, rhs): - if lhs != rhs: - raise AssertionError('%r != %r' % (lhs, rhs)) -def assertIs(lhs, rhs): - if lhs is not rhs: - raise AssertionError('%r is not %r' % (lhs, rhs)) -# Check basic code execution -result = ['Top level assignment'] -def f(): - result.append('Lower level reference') -f() -assertEqual(result, ['Top level assignment', 'Lower level reference']) -# Check the sys module -import sys -assertIs(globals(), sys.modules[__name__].__dict__) -argv0 = sys.argv[0] -""" def _make_test_script(self, script_dir, script_basename, source=None): if source is None: - source = self.test_source + source = example_source return make_script(script_dir, script_basename, source) def _check_script(self, script_name, expected_name, expected_file, - expected_argv0, expected_package): - result = run_path(script_name) - self.assertEqual(result["__name__"], expected_name) - self.assertEqual(result["__file__"], expected_file) - self.assertEqual(result["__cached__"], None) - self.assertIn("argv0", result) - self.assertEqual(result["argv0"], expected_argv0) - self.assertEqual(result["__package__"], expected_package) + expected_argv0): + # First check is without run_name + def create_ns(init_globals): + return run_path(script_name, init_globals) + expected_ns = example_namespace.copy() + expected_ns.update({ + "__name__": expected_name, + "__file__": expected_file, + "__package__": "", + "run_argv0": expected_argv0, + "run_name_in_sys_modules": True, + "module_in_sys_modules": True, + }) + self.check_code_execution(create_ns, expected_ns) + # Second check makes sure run_name works in all cases + run_name = "prove.issue15230.is.fixed" + def create_ns(init_globals): + return run_path(script_name, init_globals, run_name) + expected_ns["__name__"] = run_name + expected_ns["__package__"] = run_name.rpartition(".")[0] + self.check_code_execution(create_ns, expected_ns) def _check_import_error(self, script_name, msg): msg = re.escape(msg) @@ -336,7 +448,7 @@ argv0 = sys.argv[0] mod_name = 'script' script_name = self._make_test_script(script_dir, mod_name) self._check_script(script_name, "", script_name, - script_name, None) + script_name) def test_script_compiled(self): with temp_dir() as script_dir: @@ -345,14 +457,14 @@ argv0 = sys.argv[0] compiled_name = py_compile.compile(script_name, doraise=True) os.remove(script_name) self._check_script(compiled_name, "", compiled_name, - compiled_name, None) + compiled_name) def test_directory(self): with temp_dir() as script_dir: mod_name = '__main__' script_name = self._make_test_script(script_dir, mod_name) self._check_script(script_dir, "", script_name, - script_dir, '') + script_dir) def test_directory_compiled(self): with temp_dir() as script_dir: @@ -362,7 +474,7 @@ argv0 = sys.argv[0] os.remove(script_name) legacy_pyc = make_legacy_pyc(script_name) self._check_script(script_dir, "", legacy_pyc, - script_dir, '') + script_dir) def test_directory_error(self): with temp_dir() as script_dir: @@ -376,7 +488,7 @@ argv0 = sys.argv[0] mod_name = '__main__' script_name = self._make_test_script(script_dir, mod_name) zip_name, fname = make_zip_script(script_dir, 'test_zip', script_name) - self._check_script(zip_name, "", fname, zip_name, '') + self._check_script(zip_name, "", fname, zip_name) def test_zipfile_compiled(self): with temp_dir() as script_dir: @@ -385,7 +497,7 @@ argv0 = sys.argv[0] compiled_name = py_compile.compile(script_name, doraise=True) zip_name, fname = make_zip_script(script_dir, 'test_zip', compiled_name) - self._check_script(zip_name, "", fname, zip_name, '') + self._check_script(zip_name, "", fname, zip_name) def test_zipfile_error(self): with temp_dir() as script_dir: @@ -419,9 +531,9 @@ argv0 = sys.argv[0] def test_main(): run_unittest( - RunModuleCodeTest, - RunModuleTest, - RunPathTest + ExecutionLayerTestCase, + RunModuleTestCase, + RunPathTestCase ) if __name__ == "__main__": diff --git a/Misc/NEWS b/Misc/NEWS index 34a34c0aea2..1b2f4f41eb6 100644 --- a/Misc/NEWS +++ b/Misc/NEWS @@ -87,6 +87,9 @@ Core and Builtins Library ------- +- Issue #15230: runpy.run_path now correctly sets __package__ as described + in the documentation + - Issue #14990: Correctly fail with SyntaxError on invalid encoding declaration. @@ -341,6 +344,8 @@ Extension Modules Tests ----- +- Issue #15230: Adopted a more systematic approach in the runpy tests + - Issue #15300: Ensure the temporary test working directories are in the same parent folder when running tests in multiprocess mode from a Python build. Patch by Chris Jerdonek.