Xcode Crash on Swift 4 Conversion

Question

I have a project that I am working on in Xcode 9.1 that is currently a Swift 3 project. I get the warning from Xcode that prompts me to convert to Swift 4, but upon clicking it: Xcode crashes. Xcode also crashes when I go through Edit > Convert > To Modern Swift Syntax. I have tried restarting Xcode and my computer to no avail.

This issue only occurs in this project as I am able to convert other projects with no problems.

I have tried converting the Swift Language Version attribute in build settings to Swift 4.0, but I still get the warning.

The real kicker is that Xcode will crash but then not display the normal response to a crash (option to report to Apple, display the crash log, etc.)

What can I try to fix this? The project will still build, run, & archive but the warning is bothering my OCD.

Answer 1

If you are using XCode 9.1 and your project contains Swift Playground, try removing it. They have fixed this bug in XCode 9.2.