Hey folks, I came up against this issue and thought I’d share the solution: Running iOS tests within my multiplatform project uses

xcrun simctl spawn

command. I started getting an error when launching emulators -

domain=com.apple.CoreSimulator.SimError, code=165

xcrun simctl spawn

after XCode 11 doesn’t run in standalone mode by default. To fix you need to add

--standalone

option. This option was available since XCode 6 so should be safe to add now wherever needed. But you will only start to see this issue after upgrading to XCode 11.

Man Xcode updates are so much fun for stuff like this. My favorite was when I had tests that were launching the "iPhone XR" simulator and then they changed the name to "iPhone Xʀ"

It’s so much fun to update compiler for the new Xcode 🙂