The Windows problems seem to be ultimately caused by test modules the…

…mselves getting attached to the test result object...somewhere. Whitelisting what gets pickled in __getstate__ seems to have FINALLY solved it on my Windows VMs. Hopefully the Appveyor builders agree...

green/process.py

@@ -18,6 +18,22 @@
 
 
 
+# Super-useful debug function for finding problems in the subprocesses, and it
+# even works on windows
+def ddebug(msg, err=None): # pragma: no cover
+    """
+    err can be an instance of sys.exc_info() -- which is the latest traceback
+    info
+    """
+    if err:
+        err = ''.join(traceback.format_exception(*err))
+    else:
+        err = ''
+    sys.__stdout__.write("({}) {} {}".format(os.getpid(), msg, err)+'\n')
+    sys.__stdout__.flush()
+
+
+
 class ProcessLogger(object):
     """I am used by LoggingDaemonlessPool to get crash output out to the
     logger, instead of having process crashes be silent"""

green/result.py

@@ -164,6 +164,18 @@ def __init__(self, start_callback=None, stop_callback=None):
         super(ProtoTestResult, self).__init__(None, None)
         self.start_callback      = start_callback
         self.stop_callback       = stop_callback
+        self.pickle_attrs = [
+                'errors',
+                'expectedFailures',
+                'failures',
+                'passing',
+                'pickle_attrs',
+                'shouldStop',
+                'skipped',
+                'stderr_errput',
+                'stdout_output',
+                'unexpectedSuccesses',
+                ]
         self.reinitialize()
 
 
@@ -190,10 +202,10 @@ def __repr__(self): # pragma: no cover
 
     def __getstate__(self):
         "Prevent the callback functions from getting pickled"
-        clean_dict = self.__dict__.copy()
-        del clean_dict['start_callback']
-        del clean_dict['stop_callback']
-        return clean_dict
+        result_dict = {}
+        for pickle_attr in self.pickle_attrs:
+            result_dict[pickle_attr] = self.__dict__[pickle_attr]
+        return result_dict
 
 
     def __setstate__(self, dict):