Swift package manager fail to

I have a Swift Package with the following Package.swift manifest:

// swift-tools-version:5.1
import PackageDescription

let package = Package(
    name: "SilkUI",
    platforms: [
    products: [
            name: "SilkUI",
            type: .dynamic,
            targets: ["SilkUI"])
    targets: [
            name: "SilkUI",
            dependencies: ["CSilkUI"],
            path: "SilkUI/SilkUI"),
            name: "CSilkUI",
            path: "SilkUI/CSilkUI",
            cSettings: [

The SilkUI package is used in an Xcode project and is being included in Link Binary With Libraries and Embed Frameworks. CSilkUI contains code written in Objective-C and C.

When I try to build the Xcode project I get the following error message:

Missing required module 'CSilkUI'

When I open Package.swift and try to build everything works just fine.