# HG changeset patch
# User Ludovic Chabant <ludovic@chabant.com>
# Date 1443156101 25200
# Node ID 8fb643ea798294af0798c1c85a7f2300ec85ae39
# Parent  436f9b54d3e15a69313e6d10866f565b9d9ffd68
runtasks: Give more info if Celery is not installed.

diff -r 436f9b54d3e1 -r 8fb643ea7982 wikked/tasks.py
--- a/wikked/tasks.py	Thu Sep 24 21:26:56 2015 -0700
+++ b/wikked/tasks.py	Thu Sep 24 21:41:41 2015 -0700
@@ -1,11 +1,18 @@
 import logging
-from celery import Celery
 from wikked.wiki import Wiki, WikiParameters, BACKGROUND_CONTEXT
 
 
 logger = logging.getLogger(__name__)
 
 
+try:
+    from celery import Celery
+except ImportError:
+    logger.error("Celery is needed to run background tasks.")
+    logger.error("Install it with: pip install celery")
+    raise
+
+
 logger.debug("Creating Celery application...")
 celery_app = Celery('wikked', include=['wikked.tasks'])