Catch more errors in WorkerQueue

See #167

vdirsyncer/cli/utils.py

@@ -30,9 +30,9 @@ except ImportError:
     from configparser import RawConfigParser
 
 try:
-    from Queue import Queue
+    import Queue as queue
 except ImportError:
-    from queue import Queue
+    import queue
 
 
 cli_logger = log.get(__name__)
@@ -451,30 +451,36 @@ def parse_pairs_args(pairs_args, all_pairs):
 
 class WorkerQueue(object):
     def __init__(self, max_workers):
-        self._queue = Queue()
+        self._queue = queue.Queue()
         self._workers = []
         self._exceptions = []
         self._max_workers = max_workers
 
-    def _process_job(self):
-        func = self._queue.get()
-        try:
-            func(wq=self)
-        except:
-            if not handle_cli_error():
-                self._exceptions.append(sys.exc_info()[1])
-        finally:
-            self._queue.task_done()
+    def _worker(self):
+        while True:
+            try:
+                func = self._queue.get()
+            except (TypeError, queue.Empty):
+                # TypeError might be raised if vdirsyncer just finished
+                # processing all items and the interpreter is shutting down,
+                # yet the workers try to get new tasks.
+                # https://github.com/untitaker/vdirsyncer/issues/167
+                # http://bugs.python.org/issue14623
+                break
+
+            try:
+                func(wq=self)
+            except:
+                if not handle_cli_error():
+                    self._exceptions.append(sys.exc_info()[1])
+            finally:
+                self._queue.task_done()
 
     def spawn_worker(self):
         if self._max_workers and len(self._workers) >= self._max_workers:
             return
 
-        def worker():
-            while True:
-                self._process_job()
-
-        t = threading.Thread(target=worker)
+        t = threading.Thread(target=self._worker)
         t.daemon = True
         t.start()
         self._workers.append(t)