Xcode internal errors when testing with swift

Question

I started having peculiar problems when using XCode. Whenever I try to write test with swift, XCode shows an internal error and all the code turns white.

This happens even if I remove the @testable annotation from the code.

I tried reinstalling XCode, but this did not help. The code builds just fine so I don't have a clue where the problem might lie.

I'm unable to properly develop tests this way, my modules are not recognised, I have no error checking or code completion.

Here is a screenshot of how the problem looks:

Would love to get any guidance on this issue...

Answer 1

So I guess for now there is no good solution to this problem. It seems to be caused by crashes of SourceKit.

Fortunately the problem is not solved (partially) on my end.

I decided to make this answer a compilation of different things to try when experiencing this:

• Restart - try restarting both Xcode and the PC
• Clean the project (shift-command-K)
• Build your code, I noticed that sometimes it occurs when you just have unrelated build errors somewhere in your project - make sure it builds
• Delete the DerivedData folder rm -Rf ~/Library/Developer/Xcode/DerivedData/ , but you can also delete it from Xcode
• Delete the cache rm -Rf ~/Library/Caches/com.apple.dt.Xcode - Currently this seems to help the most

I will edit and add more solutions if I find any