Wip

Add debug statement

Author: pombredanne

src/scancode/cache.py

@@ -77,6 +77,7 @@ def scan_key(self, path, file_infos):
         Return a scan cache key for a path and file_infos.
         """
         sha1 = file_infos['sha1']
+        assert sha1
         # we may eventually store directories, in which case we use the path as a key
         return sha1 or path