$NetBSD: patch-ab,v 1.1 2013/11/26 20:36:22 drochner Exp $

avoid noise if dropbox-api is not installed

--- duplicity/backends/dpbxbackend.py.orig	2013-08-22 13:30:08.000000000 +0000
+++ duplicity/backends/dpbxbackend.py
@@ -41,7 +41,11 @@ from duplicity import tempdir
 from duplicity.backend import retry_fatal
 
 
-from dropbox import client, rest, session
+try:
+        from dropbox.session import DropboxSession
+except:
+        class DropboxSession:
+                pass
 
 # This application key is registered in my name (jno at pisem dot net).
 # You can register your own developer account with Dropbox and
@@ -100,6 +104,7 @@ def command(login_required=True):
 class DPBXBackend(duplicity.backend.Backend):
     """Connect to remote store using Dr*pB*x service"""
     def __init__(self, parsed_url):
+        from dropbox import client, rest
         duplicity.backend.Backend.__init__(self, parsed_url)
 
         self.sess = StoredSession(etacsufbo(APP_KEY)
@@ -213,7 +218,7 @@ class DPBXBackend(duplicity.backend.Back
         resp = self.api_client.file_create_folder(path)
         log.Debug('dpbx._mkdir(%s): %s'%(path,resp))
 
-class StoredSession(session.DropboxSession):
+class StoredSession(DropboxSession):
     """a wrapper around DropboxSession that stores a token to a file on disk"""
     TOKEN_FILE = _TOKEN_CACHE_FILE
 
@@ -254,7 +259,7 @@ class StoredSession(session.DropboxSessi
 
     def unlink(self):
         self.delete_creds()
-        session.DropboxSession.unlink(self)
+        DropboxSession.unlink(self)
 
 def etacsufbo(s):
   return ''.join(reduce(lambda x,y:(x and len(x[-1])==1)and(x.append(y+