Forget to make the set comprehension result a set().

jedi/evaluate/__init__.py

@@ -341,7 +341,7 @@ class Evaluator(object):
                 if isinstance(comp_for, tree.CompFor):
                     if atom.children[0] == '{':
                         # TODO dict/set comprehensions should be working.
-                        return []
+                        return set()
                     return set([iterable.Comprehension.from_atom(self, atom)])
             return set([iterable.Array(self, atom)])
 

test/completion/comprehensions.py

@@ -124,6 +124,8 @@ right
 
 #?
 {a - 1 for a in [1]}
+#? int()
+{a - 1: 3 for a in [1]}[0]
 
 # -----------------
 # name resolution in comprehensions.