Build error while trying to build a Swift-based command line tool depending on a third-party framework: this target might include its own product

Question

Context: I want to create a simple Swift command line tool using CryptoSwift I am relatively new to Xcode and Swift (and MacOS!).

Configuration:
- MacOS High Sierra 10.13.2
- Xcode: 9.2

Steps:

1. I start Xcode
2. Create a new project “Command Line tool” for MacOS
3. Option for my project:
   • Product name: cryptodemo
   • Organisation Identifier: com.demo
   • Language Swift
4. I create the project into ~/Documents

5. Fill my main.swift with:

   import Foundation
   import CryptoSwift
   
   print("Hello, World!")
   
   let bytes:Array<UInt8> = [0x01, 0x02, 0x03]
   let digest = Digest.md5(bytes)
   

6. Open the shell and go into ~/Documents/cryptodemo

7. Add CryptoSwift as a submodule as defined by the project’s README using: git submodule add https://github.com/krzyzanowskim/CryptoSwift.git
8. Open Finder and drag the CryptoSwift.xcodeproj file into my Xcode project

9. In Xcode, I go into my project Build Phase

   • I added CryptoSwift as a target dependency
   • I added CryptoSwift.framework to Link Binaries with Libraries
   • I added CryptoSwift.framework to Copy Files with:
     • Destination: Framework
     • SubPath: (empty)

10. Then I build it. I have this error:

    Check dependencies
    
    Unable to run command 'PBXCp CryptoSwift.framework' - this target might include its own product.
    Unable to run command 'CodeSign A' - this target might include its own product.
    

    

Here is the archive of the project cryptodemo.zip

Answer 1

The only way I managed to build a command line tool using a third-party Swift libraries is to use Swift Package Manager (SPM).

Example of Swift project using SPM (that could be generated using swift package init --type executable):

// swift-tools-version:4.0
// The swift-tools-version declares the minimum version of Swift required to build this package.

import PackageDescription

let package = Package(
    name: “mytool”,
    dependencies: [
        .package(url: "https://github.com/myfreeweb/SwiftCBOR.git", .branch("master")),
    ],
    targets: [
        // Targets are the basic building blocks of a package. A target can define a module or a test suite.
        // Targets can depend on other targets in this package, and on products in packages which this package depends on.
        .target(
            name: “mytool”,
            dependencies: [ "SwiftCBOR" ]),
    ]
)

A Xcode project could be generated from this SPM using: swift package generate-xcodeproj