for me it works great, a few quirks to configure xcode at first (like with most things in xcode when you need more than a 100% cocoa app), then now the workflow

for me it works great, a few quirks to configure xcode at first (like with most things in xcode when you need more than a 100% cocoa app), then now the workflow is unobtrusive. debugging also works from xcode, minus coloring of rust code. my only concern is bitcode support, not feasible now due to a version mismatch between apple's llvm and rust's llvm (you can emit bitcode with rustc). which means currently you can ship apps for iOS, but not watchOS or tvOS. (my use case of rust is DSP / audio synthesis)