got errors when building jsonkit with cocoapods, found out they changed compile flag here https://github.com/CocoaPods/Specs/blob/017c423e46e58049b7f68b2ac9d901533d515132/JSONKit/1.5pre/JSONKit.podspec

JSONKit.podspec

Pod::Spec.new do |s|
  s.name     = 'JSONKit'
  s.version  = '1.5pre'
  s.license  = 'BSD / Apache License, Version 2.0'
  s.summary  = 'A Very High Performance Objective-C JSON Library.'
  s.homepage = 'https://github.com/johnezang/JSONKit'
  s.author   = 'John Engelhart'
  s.source   = { :git => 'https://github.com/johnezang/JSONKit.git', :commit => '0aff3deb5e1bb2bbc88a83fd71c8ad5550185cce' }

  s.source_files   = 'JSONKit.*'
  s.compiler_flags = '-Wno-deprecated-objc-isa-usage', '-Wno-format'
end