Index: ubuntuone-client-1.0.1/ubuntuone/oauthdesktop/auth.py
===================================================================
--- ubuntuone-client-1.0.1.orig/ubuntuone/oauthdesktop/auth.py
+++ ubuntuone-client-1.0.1/ubuntuone/oauthdesktop/auth.py
@@ -40,6 +40,7 @@ from twisted.web import server, resource
 from ubuntuone.oauthdesktop.logger import setupLogging
 logger = setupLogging("UbuntuOne.OAuthDesktop.auth")
 
+CA_CERTS = "/etc/ssl/certs/ca-certificates.crt"
 
 class NoAccessToken(Exception):
     """No access token available."""
@@ -61,7 +62,7 @@ def _connect_wrapper(self):
         self._tunnel()
     self.sock = ssl.wrap_socket(sock, self.key_file, self.cert_file,
         cert_reqs=ssl.CERT_REQUIRED, 
-        ca_certs="/etc/ssl/certs/ca-certificates.crt")
+        ca_certs=CA_CERTS)
 httplib.HTTPSConnection.connect = _connect_wrapper
 
 class FancyURLOpenerWithRedirectedPOST(urllib.FancyURLopener):
@@ -218,6 +219,13 @@ class AuthorisationClient(object):
     def make_token_request(self, oauth_request):
         """Perform the given `OAuthRequest` and return the associated token."""
         
+        # if the certificate file is not there this will fail with an obtuse
+        # error message, so check in a friendly way first.
+        if not os.path.exists(CA_CERTS):
+            self._forward_error_callback(Exception(
+                "Certificate file %s does not exist!" % CA_CERTS))
+            return
+
         logger.debug("Making a token request")
         # Note that we monkeypatched httplib above to handle invalid certs
         # Ways this urlopen can fail: