Xcode is not working under Rosetta anymore on macOS 12 on Apple Silicon

It could be a beta 1 issue but I prefer to warn you.

Update: Apple mention the issue in Xcode 13 beta 2 release note, and even link it to the feedback I’ve made:

Xcode and xcodebuild may fail to build iOS, tvOS, and watchOS projects under Rosetta in macOS 12. (78967162) (FB9130594)

So it might get fixed in an upcoming beta of macOS!

If like me you was relying on Xcode running under Rosetta on your Apple Silicon computer for some projects (which use outdated 3rd-party libraries without arm-64 simulators binaries), be careful when if you plan to install macOS 12 beta 1. It’s working fine on Big Sur, but not on macOS 12 for now.

I’ve asked Apple here:

Can't compile on Xcode running und... | Apple Developer Forums

And apparently it was never intended to be a supported configuration even on Big Sur, and it’ll not be supported in the future. But again, could just be a beta 1 bug.

I’ve tried to dig in a bit, but I didn’t spent to much time on it, basically IBCocoaTouchImageCatalogTool which is a process used to compile assets catalogs among other things can’t be launched. Same for cdtool, which is used to compile code data models files, it throw the same error:

Anyway, it’s just a note, not a very big deal at the moment as those librairies will soon be gone from the problematic project.

But if you too you’re using this workflow, you’re welcome to chime in the thread or in the comments here.

Happy coding!