The MacBook Pro almost hang the other day, press a key or click some function then the cursor turned into spinning rainbow.
Check the cpu usage in terminal console and find that “Interface Builder” was the highest cpu usage process.
Google and found the solution and it worked for me. It might work for you if there’re “Toolbar” component in your storyboard.
1.Open storyboard as “Source
2.Change “translatedAutoresizingMaskIntoConstraints” attribute of “Toolbar” from “NO” to “YES”