When building a huge iOS or OSX project with lots of files we get very long build times. Using plugin version 1.33 build time is around 9 minutes and using plugin version 1.4 it takes about 40 minutes (everything else is the same). From my research, the build itself is finished after the same 9 minutes (output exists in the workspace) but the job is not reported as finished due to very big xcodebuild output that is still being processed on the Jenkins server. During this whole time the thread responsible for the slave connection is busy 100% taking whole core(also, console is in lag - you can see as if build is still running).

Looks like the xcode output parser feature (using regex) that was introduced in 1.4 is not very efficient in terms of CPU usage. That creates the lag in console output and the job end time itself.