dyld: Library not loaded: @rpath/libswiftCore.dylib problem with new Xcode (10.2)

Swift 5 Runtime Support for Command Line Tools Package Starting with Xcode 10.2, Swift command line tools require the Swift libraries in macOS. They’re included by default starting with macOS Mojave 10.14.4. In macOS Mojave 10.14.3 and earlier, there’s an optional package to provide these runtime support libraries for Swift command line tools that you can download from More Downloads for Apple Developers. If you installed the beta version of this package, replace it with the release version. This package is only needed for Swift command line tools, not for apps with graphical user interfaces.

Note that:

  • This is only necessary if you are still on macOS 10.14.3. As soon as macOS is upgraded to 10.14.4, the Swift runtime libraries are provided by the operating system, and command line tools created with Xcode 5 run without the need to install the “Swift 5 Runtime package.”
  • On macOS 10.14.3 with Xcode 10.2 you must download and install the latest “Swift 5 Runtime package.” An earlier package which you might have installed with an Xcode 10.2 beta release does not work.
  • Early versions of the Xcode 10.2 beta release notes recommended to add a user-defined setting SWIFT_FORCE_STATIC_LINK_STDLIB=YES as a workaround, that is no longer necessary.