fix #20

Author: leavez

lib/cocoapods-binary/Integration.rb

@@ -154,9 +154,10 @@ def remove_target_files_if_needed
             prebuilt_specs.each do |spec|
                 # `spec` may be a subspec, so we use the root's name 
                 root_name = spec.root.name
+                target = name_to_target_hash[root_name]
+                next unless target.should_build?
 
                 # use the prebuilt framework
-                target = name_to_target_hash[root_name]
                 original_vendored_frameworks = spec.attributes_hash["vendored_frameworks"] || []
                 if original_vendored_frameworks.kind_of?(String)
                     original_vendored_frameworks = [original_vendored_frameworks]