I recently wrote a tool to report Swift block compile times, since this kind of thing can be unpredictable. At Hipmunk we run it every night to find out how we can make our builds faster.<p>Another common culprit of slow compile times is usage of lazy var.<p><a href="https:&#x2F;&#x2F;github.com&#x2F;irskep&#x2F;swift_compile_times_parser" rel="nofollow">https:&#x2F;&#x2F;github.com&#x2F;irskep&#x2F;swift_compile_times_parser</a>