Same here!

Same here

Same here

Submitted FB FB15092093 for this

It seems to be corrected now for me. Just started Xcode in the morning and the usual download, which should start and fail, succeeded.

Can confirm that this is happening on iOS 18.0 RC with Xcode 16 RC when in Swift 6.0 mode and optimisations enabled. When optimisations are not enabled, or if we're in Swift 5 mode, the crash does not occur. From what I see the crash is with an assert - so the issue may be an assert in iOS that assumes the asynchronous renderer is being tied to a specific dispatch queue, and the optimised build possibly does not tie the renderer into a specific dispatch queue, as it possibly uses an actor. I hope this additional input helps. It would be a shame if we can't compile for Swift 6.0 for iOS 18.0, I hope this gets fixed... Edit: Found the exception text too: EXC_BREAKPOINT: BUG IN CLIENT OF LIBDISPATCH: Assertion failed: Block was expected to execute on queue [com.apple.main-thread (0x1eee64a80)] > com.apple.main-thread

@DTS Engineer Thanks for your response, but that thread is about shipping App Store builds to customers, so it answers a different question. My question is specifically about submitting builds to TestFlight (e.g. alpha and/or beta testing). What I'm not sure about given the feedback from Xcode Cloud is whether support hasn't been added yet for Icon Composer assets in TF, or if I need to add more assets along with the new Icon Composer asset on TF uploads. The docs seem to imply just the Icon Composer asset is needed, but then there's this error that seems to imply that there are news to come about that..?

@pegasusspiele I don't think that's the case, as I've selected Tahoe and Xcode 26 for the build environment in those workflows. The fact that the error at the end refers to Icon Designer definitely implies to me that the toolchain is the most recent one.

Same :(