This error message can occur when running any command tool, or an app which calls a command tool, in 10.14.3 and earlier.
Swift 5.0
Release notes, three major bugs fixed (and plenty more too I suspect) – that’s got to be good. But there’s also the matter of broken command tools on previous versions.
Ready to download updates to macOS, iOS, watchOS, Xcode, and some security updates, all at once? It looks like we’re going to be busy next week.
How many apps should launch faster, deliver better performance, be smaller, and use less memory than they have in the past.
The Eclectic Light Company 