I noticed that Xcode 7.3 always keep building, even in idle time. This loads CPU much, so sometimes it stops responding. Does anyone have an idea how to turn of this "feature"?
This may be related with mutli-target workspace, cause usually it builds different targets, not currently selected.
in XCode: Editor > Automatically Refresh Views
Unselect it and re-run project. Thats it!
After some time struggling this, I finally solved this issue.
Xcode started idle build right after I open Interface Builder. Removing @IBDesignable across all project solved this, so I hope this issue can be solved in future Xcode updates to get using @IBDesignable again.
Going along with @oleg-kohtenko's answer, closing all Interface Builder windows seems to fix the issue without the need to remove @IBDesignable.
And if you aren't really using IBDesignable, you can still use IBInspectable attributes without causing the building problem.
Just my two cents if designables agent gets hang on Xcode 9. If you were visualizing the problematic storyboard as iPhone X, edit such storyboard file as source code (right click -> open as -> source code).
Near the top, you'll see a xml block stating
<device id=“retina5_9” ...>
<adaptation id="fullscreen"/>
</device>
Change the id to “retina5_5” (iPhone plus, just the option I used, I’m assuming others would work).
Save and open the file as interface builder and you should be fine. Now take the time and file a bug report :D
Happy coding!
来源：https://stackoverflow.com/questions/36335335/xcode-7-3-constantly-building-in-idle