Swift Package Manager Mixed Language Source Files

Question

For some reason when I try to run swift build on my Package.swift file:import PackageDescription

let package = Package(
    name: "mobile-HDISegurado-ios",
    dependencies: [
        .package(url: "https://github.com/watson-developer-cloud/swift-sdk", from: "0.30.0"),
        ],
    targets: [
        .target(
            name: "mobile-HDISegurado-ios",
            dependencies: ["WatsonDeveloperCloud"],
            path: "mobile-HDISegurado-ios",
            exclude: [
                "Config",
                "Public",
                "Resources",
                ]
        )
    ] )

I've got the following error:

error: target at '.../mobile-HDISegurado-ios' contains mixed language source files; feature not supported

More details:

• swift package tools-version: 4.1.0
• project workspace with Cocoapods running.

Answer 1

Are you building iOS project using SPM? Currently SPM doesn't have iOS support. Although, there is a 3rd party tool that fills that gap: https://swiftxcode.github.io/

If you're building for other else then you can't have Swift file and other C family language file mixed. I had the same problem because there was one Objective-C file inside my target path. All I did was to include the file name inside the exclude array.

So, make sure to ignore Objective-C classes if you have one inside " mobile-HDISegurado-ios " by passing the file name inside the exclude parameter.

Answer 2

For Xcode 11 and Above / 2020 Solution

Also if you added Swift files in Objective-C project or workspace, but later removed all Swift files, Xcode still keeps some entries under Build Settings. Check for Swift related options there like line below:

• SWIFT_INSTALL_OBJC_HEADER
• SWIFT_OPTIMIZATION_LEVEL
• SWIFT_VERSION

If you remove those options, Xcode will not give error anymore, you can safely install your Package without any hassle.

Tested with:

• swift-tools-version:5.1
• Xcode 11.3

Best.

Answer 3

SPM now supports mixed language source files, but you may have to separate them into multiple targets.

From the relevant docs :

Targets can contain Swift, Objective-C/C++, or C/C++ code, but an individual target can't mix Swift with C-family languages. For example, a Swift package can have two targets, one that contains Objective-C, Objective-C++, and C code, and a second one that contains Swift code.

In practice, you should move your ObjC/C/C++ files into one directory, move your Swift files into another directory, and then modify your Package.swift thus:

products: [
    .library(
        name: "MyLibrary",
        targets: ["MyLibrary"]),
],
.target(name: "MyLibraryObjC",
        path: "Sources/MyLibraryObjC"
),
.target(name: "MyLibrarySwift",
        path: "Sources/MyLibrarySwift"
)