- fixed collection errors incorrectly being handled as process crashes;

- added handling of exceptions in subprocesses, more or less passing
  them on to parent processes.  This is not perfect: the traceback is
  likely lost as the exception is serialized.  Still, this now correctly
  leads to INTERRUPTED exit status when appropriate;

src/pytest_cleanslate/__version__.py

@@ -1 +1 @@
-__version__ = "1.0.5"
+__version__ = "1.0.6"

src/pytest_cleanslate/plugin.py

@@ -35,7 +35,7 @@ def runtest(self):
 
     def collect_and_run(self):
         # adapted from pytest-forked
-        import marshal
+        import pickle
         import _pytest
         import pytest_forked as ptf # FIXME pytest-forked is unmaintained
         import py                   # FIXME py is maintenance only
@@ -52,7 +52,16 @@ def collect_items(collector):
                     else:
                         yield it
 
-            self.session.items = list(collect_items(module))
+            try:
+                self.session.items = list(collect_items(module))
+            except BaseException:
+                excinfo = pytest.ExceptionInfo.from_current()
+                return pickle.dumps([pytest.CollectReport(
+                            nodeid=self.nodeid,
+                            outcome='failed',
+                            result=None,
+                            longrepr=self._repr_failure_py(excinfo, "short"))
+                ])
 
             pm = self.config.pluginmanager
             caller = pm.subset_hook_caller('pytest_collection_modifyitems', remove_plugins=[self.parent.plugin])
@@ -70,8 +79,10 @@ def pytest_runtest_logreport(self, report):
                 self.ihook.pytest_runtestloop(session=self.session)
             except (pytest.Session.Interrupted, pytest.Session.Failed):
                 pass
+            except BaseException as e:
+                return pickle.dumps(e)
 
-            return marshal.dumps([self.config.hook.pytest_report_to_serializable(config=self.config, report=r) for r in reports])
+            return pickle.dumps(reports)
 
         with IgnoreOsCloseErrors():
             ff = py.process.ForkedFunc(runforked)
@@ -80,7 +91,11 @@ def pytest_runtest_logreport(self, report):
         if result.retval is None:
             return [ptf.report_process_crash(self, result)]
 
-        return [self.config.hook.pytest_report_from_serializable(config=self.config, data=r) for r in marshal.loads(result.retval)]
+        retval = pickle.loads(result.retval)
+        if isinstance(retval, BaseException):
+            raise retval
+
+        return retval
 
 
 class CleanSlateCollector(pytest.File, pytest.Collector):
@@ -92,6 +107,32 @@ def collect(self):
         yield CleanSlateItem.from_parent(parent=self, name=self.name)
 
 
+def run_item_forked(item):
+    import _pytest.runner
+    import pytest_forked as ptf # FIXME pytest-forked is unmaintained
+    import py                   # FIXME py is maintenance only
+    import pickle
+
+    def runforked():
+        try:
+            return pickle.dumps(_pytest.runner.runtestprotocol(item, log=False))
+        except BaseException as e:
+            return pickle.dumps(e)
+
+    ff = py.process.ForkedFunc(runforked)
+    result = ff.waitfinish()
+
+    if result.retval is None:
+        return [ptf.report_process_crash(item, result)]
+
+    retval = pickle.loads(result.retval)
+
+    if isinstance(retval, BaseException):
+        raise retval
+
+    return retval
+
+
 class CleanSlatePlugin:
     """Pytest plugin to isolate test collection, so that if a test's collection pollutes the in-memory
        state, it doesn't affect the execution of other tests."""
@@ -104,15 +145,13 @@ def pytest_pycollect_makemodule(self, module_path: Path, parent):
 
     @pytest.hookimpl(tryfirst=True)
     def pytest_runtest_protocol(self, item: pytest.Item, nextitem: pytest.Item):
-        import pytest_forked as ptf # FIXME pytest-forked is unmaintained
-
         ihook = item.ihook
         ihook.pytest_runtest_logstart(nodeid=item.nodeid, location=item.location)
         if isinstance(item, CleanSlateItem):
             reports = item.collect_and_run()
         else:
             # note any side effects, such as setting session.shouldstop, are lost...
-            reports = ptf.forked_run_report(item)
+            reports = run_item_forked(item)
 
         for rep in reports:
             ihook.pytest_runtest_logreport(report=rep)

tests/test_cleanslate.py

@@ -17,7 +17,8 @@ def seq2p(tests_dir, seq):
     'assert': 'assert False',
     'exception': 'raise RuntimeError("test")',
     'kill': 'os.kill(os.getpid(), 9)',
-    'exit': 'pytest.exit("goodbye")',
+#    'exit': 'pytest.exit("goodbye")', # FIXME add support
+    'exit': 'sys.exit(0)',
     'interrupt': 'raise KeyboardInterrupt()'
 }
 
@@ -107,7 +108,7 @@ def test_check_suite_fails(tests_dir, pollute_in_collect, fail_collect, fail_kin
                         fail_collect=fail_collect, fail_kind=fail_kind)
 
     p = subprocess.run([sys.executable, '-m', 'pytest', tests_dir], check=False)
-    if fail_collect or fail_kind in ('exit', 'interrupt'):
+    if fail_collect or fail_kind == 'interrupt':
         assert p.returncode == pytest.ExitCode.INTERRUPTED
     else:
         assert p.returncode == pytest.ExitCode.TESTS_FAILED
@@ -154,9 +155,38 @@ def test_foo():
 {'test_foo()' if fail_collect else ''}
 """)
 
-    p = subprocess.run([sys.executable, '-m', 'pytest', '--cleanslate', tests_dir], check=False)
+    p = subprocess.run([sys.executable, '-m', 'pytest', '--cleanslate', tests_dir], check=False,
+                       capture_output=True)
+    print(failing.read_text())
+    assert p.returncode == (pytest.ExitCode.INTERRUPTED if (fail_kind == 'interrupt' and not fail_collect)
+                            else pytest.ExitCode.TESTS_FAILED)
+
+    # pytest-forked error message that shouldn't be used unless the process was truly killed
+    assert 'CRASHED with signal 0' not in str(p.stdout, 'utf-8')
+
+
+def test_collect_failure(tests_dir):
+    # _unconditionally_ failing test
+    failing = seq2p(tests_dir, 1)
+    failing.write_text(f"""\
+import sys
+import os
+import pytest
+
+def test_foo():
+    failure()
+
+assert False
+""")
+
+    p = subprocess.run([sys.executable, '-m', 'pytest', '--cleanslate', tests_dir], check=False,
+                       capture_output=True)
+    # FIXME collection errors should show as interrupted
     assert p.returncode == pytest.ExitCode.TESTS_FAILED
 
+    # pytest-forked error message that shouldn't be used unless the process was truly killed
+    assert 'CRASHED with signal 0' not in str(p.stdout, 'utf-8')
+
 
 def test_isolate_module_yields_collector(tests_dir):
     # A pytest.Collector.collect()'s return value may include not only pytest.Item,