Twitter绑定

当我一点击“Link My Twitter Account”的按钮就出现：

Traceback (most recent call last):
File "/base/python_runtime/python_lib/versions/1/google/appengine/ext/webapp/__init__.py", line 511, in __call__
handler.get(*groups)
File "/base/data/home/apps/v2ex/1.343564127440067233/t.py", line 48, in get
request_token = twitter.getRequestToken()
File "/base/data/home/apps/v2ex/1.343564127440067233/twitter/oauthtwitter.py", line 189, in getRequestToken
resp = self._FetchUrl(url, no_cache=True)
File "/base/data/home/apps/v2ex/1.343564127440067233/twitter/oauthtwitter.py", line 101, in _FetchUrl
url_data = opener.open(url).read()
File "/base/python_runtime/python_dist/lib/python2.5/urllib2.py", line 381, in open
response = self._open(req, data)
File "/base/python_runtime/python_dist/lib/python2.5/urllib2.py", line 399, in _open
'_open', req)
File "/base/python_runtime/python_dist/lib/python2.5/urllib2.py", line 360, in _call_chain
result = func(*args)
File "/base/python_runtime/python_dist/lib/python2.5/urllib2.py", line 1115, in https_open
return self.do_open(httplib.HTTPSConnection, req)
File "/base/python_runtime/python_dist/lib/python2.5/urllib2.py", line 1080, in do_open
r = h.getresponse()
File "/base/python_runtime/python_dist/lib/python2.5/httplib.py", line 197, in getresponse
self._allow_truncated, self._follow_redirects)
File "/base/python_runtime/python_lib/versions/1/google/appengine/api/urlfetch.py", line 241, in fetch
return rpc.get_result()
File "/base/python_runtime/python_lib/versions/1/google/appengine/api/apiproxy_stub_map.py", line 501, in get_result
return self.__get_result_hook(self)
File "/base/python_runtime/python_lib/versions/1/google/appengine/api/urlfetch.py", line 325, in _get_fetch_result
raise DownloadError(str(err))
DownloadError: ApplicationError: 2