Update swift-5.0-branch?

beefon · June 25, 2019, 9:12am

I depend on SPM package in my project. I depend on swift-5.0-branch. Also, I still use Swift 4.2 and Swift 5.0 at the same time for different SPM tools I develop. swift-5.0-branch happened to build with both Swift versions.

After merging a9367490 I can no longer build my products because swift-llbuild dependency now lacks Swift 4.2 package file. That happens because SPM depends on master branch of swift-llbuild.

I wonder if you could push a fix to swift-5.0-branch of SPM so it could still be buildable for older Swift versions like it was before. I could open a PR, but I wonder what swift-llbuild commit should be used, I guess dependency should be declared as .revision("")?

cc @ddunbar , @Aciid

beefon · June 25, 2019, 9:39am

It looks like without the latest commit in swift-llbuild SPM target builds in Swift 4.2 environment.

I've also tried to use swift-llbuild's swift-5.0-branch, but build fails for some not very obvious reason. That's strange though, I expected a SPM's swift-5.0-branch + llbuild's swift-5.0-branch to work together without any issues.

SDGGiesbrecht · June 25, 2019, 10:30pm

Branches are in flux by definition. Is there a reason you cannot depend on a semantic version? 0.4.0 is the latest. If you can’t, then depending on specific revisions yourself is probably wiser, and I would probably use the swift-X.X-RELEASE tags as starting points when you are trying to find working revisions.

beefon · June 25, 2019, 11:33pm

Whatever version I'd depend on, SPM will still refer to master branch of llbuild, that would still break my flow. The issue is that SPM does not have a fixed version for its dependency, so changes inside llbuild might break projects that depend on it transitively.

SDGGiesbrecht · June 25, 2019, 11:58pm

The semantic versions of SwiftPM do rely in turn on semantic versions of LLBuild.

github.com

apple/swift-package-manager/blob/0.4.0/Package.swift#L262


      
          // this right now.
          
          
#if os(Linux)
          import Glibc
          #else
          import Darwin.C
          #endif
          
          
if getenv("SWIFTPM_BOOTSTRAP") == nil {
              package.dependencies += [
                  .package(url: "https://github.com/apple/swift-llbuild.git", "0.1.0"..<"0.2.0"),
              ]
              package.targets.first(where: { $0.name == "SPMLLBuild" })!.dependencies += ["llbuildSwift"]
          }
          
          
if getenv("SWIFTPM_BUILD_PACKAGE_EDITOR") != nil {
              package.targets += [
                  .target(name: "SPMPackageEditor", dependencies: ["Workspace", "SwiftSyntax"]),
                  .target(name: "swiftpm-manifest-tool", dependencies: ["SPMPackageEditor"]),
                  .testTarget(name: "SPMPackageEditorTests", dependencies: ["SPMPackageEditor", "TestSupport"]),
              ]

Only evolving branches of SwiftPM depend on evolving branches of LLBuild.

beefon · June 26, 2019, 8:21am

Thanks for pointing to this, I appreciate your help.

beefon · June 26, 2019, 9:48am

Anyway, even 0.4.0 is not usable with Swift 4.2 toolchain.

'llbuild' /...../.build/checkouts/swift-llbuild.git--4550182610071526611: 
error: could not find source files for target(s): llvmDemangle; 
use the 'path' property in the Swift 4 manifest to set a custom target path
'SwiftPM' /...../.build/checkouts/swift-package-manager.git--1970998161319157756: 
error: product dependency 'llbuildSwift' not found

If I switch to // swift-tools-version:5.0 toolchain, it works.

Aciid · June 26, 2019, 4:16pm

You shouldn't be using SwiftPM's Swift 5 branch with the Swift 4.2 toolchain.