Apparently python 3.4+ removes the __func__ attribute, sigh

src/calibre/devices/interface.py

@@ -251,6 +251,7 @@ class DevicePlugin(Plugin):
         '''
 
         return True
+    can_handle.is_base_class_implementation = True
 
     def open(self, connected_device, library_uuid):
         '''

src/calibre/devices/usbms/device.py

@@ -211,8 +211,7 @@ class Device(DeviceConfig, DevicePlugin):
         return drives
 
     def can_handle_windows(self, usbdevice, debug=False):
-        from calibre.devices.interface import DevicePlugin
-        if self.can_handle.__func__ is DevicePlugin.can_handle.__func__:
+        if hasattr(self.can_handle, 'is_base_class_implementation'):
             # No custom can_handle implementation
             return True
         # Delegate to the unix can_handle function, creating a unix like

src/calibre/web/feeds/news.py

@@ -1117,7 +1117,7 @@ class BasicNewsRecipe(Recipe):
 
     def _fetch_article(self, url, dir_, f, a, num_of_feeds):
         br = self.browser
-        if self.get_browser.__func__ is BasicNewsRecipe.get_browser.__func__:
+        if hasattr(self.get_browser, 'is_base_class_implementation'):
             # We are using the default get_browser, which means no need to
             # clone
             br = BasicNewsRecipe.get_browser(self)
@@ -1787,6 +1787,7 @@ class CalibrePeriodical(BasicNewsRecipe):
                     ' the calibre Periodicals service.'))
 
         return br
+    get_browser.is_base_class_implementation = True
 
     def download(self):
         self.log('Fetching downloaded recipe')