Fix for https://github.com/CocoaPods/CocoaPods/pull/5578

lib/cocoapods/resolver.rb

@@ -473,12 +473,7 @@ module Pod
     #         dependencies for `target`.
     #
     def valid_dependencies_for_target_from_node(target, dependencies, node)
-      cache_dependency = dependencies[node.name]
-
-      if cache_dependency
-        return cache_dependency
-      end
-
+      dependencies[node.name] ||= begin
         validate_platform(node.payload, target)
         dependency_nodes = node.outgoing_edges.select do |edge|
           edge_is_valid_for_target?(edge, target)
@@ -487,12 +482,13 @@ module Pod
         dependency_nodes + dependency_nodes.flat_map do |item|
           node_result = valid_dependencies_for_target_from_node(target, dependencies, item)
 
-        dependencies[item.name] = node_result
-
           node_result
         end
       end
 
+      dependencies[node.name]      
+    end
+
     # Whether the given `edge` should be followed to find dependencies for the
     # given `target`.
     #