Xcode 9.4 : unexpected service error: The Xcode build system has crashed

Question

I’m getting strange error while building project in Xcode 9.4

Build system information - unexpected service error: The Xcode build system has crashed. Please close and reopen your workspace.

I tried Xcode quit and reopen but that didn’t worked. Any solution?

Answer 1

Please clear derived data folder (located at ~/Library/Developer/Xcode/DerivedData) and restart the Xcode project.

Answer 2

This error usually happens between Xcode major versions. Apple usually claim their new build system is ** times faster than their previous version. If you see this error(I see this on changing Xcode9 to Xcode10 beta), you can always change it to the legacy build system. Here is how you can do this:

1. Open 'workspace settings'( it is now changed to 'Project Settings' if you are using Xcode10 or later) in the File Menu
2. Change build system to 'legacy'