Xcode 12.2: crashes when assign static property in init

I don't understand what you do to make it work (where do you call CoreDataFixture)
nor the original code: what is the line 4 with a colon only ?

Hi Claude,

I update my question here:

The case it crashes with XCode 12.2

Code Block 
final class CoreDataFixture {	
	var selfUserProvider: SelfUserProvider!	
	init() {
		/// some other init code		
		selfUserProvider = SelfUserProvider()
		SelfUser.provider = selfUserProvider	
	}
}
let coreDataFixture = CoreDataFixture()

I refactored to below and doesn't crash:

Code Block 
final class CoreDataFixture {	
	var selfUserProvider: SelfUserProvider!	
	init() {
		// some other init code		
		selfUserProvider = SelfUserProvider()
	}
}
let coreDataFixture = CoreDataFixture()
SelfUser.provider = coreDataFixture.selfUserProvider	

However I rerun this part today and it works. This class is defined in test target. The crash EXC_BAD_ACCESS occurs when calling static method in init/deinit methods, not only when calling SelfUser.provider = selfUserProvider