Swift Package Manager - UIKit Dependency

You have to change some swiftc options to build the project against proper sdk and target

swift build -Xswiftc "-sdk" -Xswiftc "`xcrun --sdk iphonesimulator --show-sdk-path`" -Xswiftc "-target" -Xswiftc "x86_64-apple-ios13.0-simulator"

The Swift Package Manager builds executables to run on OS X (or Linux); UIKit is a framework in iOS and won't be accessible.

It may be iOS, tvOS and others become accessible as Swift Package Manager evolves.

On Dec 4, 2015, at 5:39 PM, Daniel Dunbar (@apple.com) wrote:

...

Right, now we only compile for the host platform (OS X or Linux, currently). Among other things, we currently have no knowledge (or options to choose) what SDK or architecture you are targeting. We also have no mechanisms for specifying what platforms targets are compatible with in the manifest.

Make it work without limit the platforms:

You should select an iOS-based target to make it available:

_{If you leave it selecting macOS (by default), you will get the error.}

---

Limit to a specific platform

if you want your package to be available only for specific platforms (for example only for iOS), you should specify the platform in the package.swift file:

let package = Package(
    name: "MyLibrary",
    platforms: [
        .iOS(.v10)
    ],
    products: [
,,,

---

Support Multiplatform

If you need your framework to be available on multiple platforms, don't forget to check the availability of the imported framework like:

#if canImport(UIKit)

import UIKit

#endif

Currently Swift Package Manager has full Xcode support. I was able to get around this error by specifying in my Package.swift manifest that the platform was iOS.

let package = Package(
    name: "MyPackage",
    platforms: [
        .iOS(.v8)
    ],

Then you can open the Package.swift file in Xcode and it will just work.