SPM cannot resolve dependency graph

adtrevor · March 31, 2019, 1:19am

Hello,

I have an issue where, in one package I forked, I modified Package.swift so that one dependency points to the master branch of another package I forked.

.package(url: "https://github.com/adtrevor/http.git", .branch("master")),

Unfortunately, the package resolution errors with an unclear message:

websocket$ swift package show-dependencies

Fetching GitHub - PopFlamingo/http: 🚀 Non-blocking, event-driven HTTP built on Swift NIO.

Updating GitHub - apple/swift-nio-ssl: TLS Support for SwiftNIO, based on BoringSSL.

Updating GitHub - vapor/core: 🌎 Utility package containing tools for byte manipulation, Codable, OS APIs, and debugging.

Updating GitHub - apple/swift-nio: Event-driven network application framework for high performance protocol servers & clients, non-blocking.

Updating GitHub - vapor/open-crypto: 🔑 Hashing (BCrypt, SHA2, HMAC), encryption (AES), public-key (RSA), and random data generation.

Updating GitHub - apple/swift-nio-zlib-support

Updating GitHub - apple/swift-nio-ssl-support

Updating GitHub - apple/swift-nio-http2: HTTP/2 support for SwiftNIO

Updating GitHub - apple/swift-nio-extras: Useful code around SwiftNIO.

Updating GitHub - apple/swift-log: A Logging API for Swift

error: dependency graph is unresolvable; found these conflicting requirements:

Dependencies:

GitHub - PopFlamingo/http: 🚀 Non-blocking, event-driven HTTP built on Swift NIO. @ master

I don't understand at all what is happening. Is this a bug or am I doing something wrong?

Thank you

cc: @Aciid Is this something that will get better error messages similar to SwiftPM: what's the conflict? ? I can't find at all the cause with the current error

Aciid · March 31, 2019, 3:22pm

There is work going on in SwiftPM that will dramatically improve the dependency resolution error messages. It's not all there yet but I just ran the new resolver on your package and got this:

because http @master depends on swift-nio-ssl ^2.0.0 and websocket depends on http @master, websocket requires swift-nio-ssl.
And because websocket depends on swift-nio-ssl ^1.3.1 and root depends on websocket, version solving failed.

To pin point, here are the conflicts:

github.com

PopFlamingo/http/blob/master/Package.swift#L14


      
          let package = Package(
              name: "http-kit",
              products: [
                  .library(name: "HTTPKit", targets: ["HTTPKit"]),
              ],
              dependencies: [
                  // Event-driven network application framework for high performance protocol servers & clients, non-blocking.
                  .package(url: "https://github.com/apple/swift-nio.git", from: "2.0.0"),
                  
                  // Bindings to OpenSSL-compatible libraries for TLS support in SwiftNIO
                  .package(url: "https://github.com/apple/swift-nio-ssl.git", from: "2.0.0"),
                  
                  // HTTP/2 support for SwiftNIO
                  .package(url: "https://github.com/apple/swift-nio-http2.git", from: "1.0.0"),
                  
                  // Useful code around SwiftNIO.
                  .package(url: "https://github.com/apple/swift-nio-extras.git", from: "1.0.0"),
                  
                  // Swift logging API
                  .package(url: "https://github.com/apple/swift-log.git", .branch("master")),
              ],

https://github.com/adtrevor/websocket/blob/master/Package.swift#L23

adtrevor · March 31, 2019, 3:31pm

Thanks a lot! Nice to see the improvement for the messages! :)

SDGGiesbrecht · April 1, 2019, 1:29am

@kiliankoe might be encouraged to see that his work already came in useful. (You too Ankit, but you already know.)

evanagomes · April 1, 2019, 9:08am

This also not working properly on my iOS device. It is showing iTunes has an invalid signature. Please help me to fix this properly.