Unable to build tests on Linux with swift-parsing 0.13.0 as dependency

[finestructure]

I've been trying to bump swift-parsing to the latest release 0.13.0 (from 0.12.0) but I'm getting a build error when running tests on Linux (swift test). It all works fine on macOS.

I've created a stripped down reproducer:

mkdir test ; cd test
swift package init

with the following manifest:

// swift-tools-version: 5.9

import PackageDescription

let package = Package(
    name: "test",
    products: [
        .library(name: "test", targets: ["test"]),
    ],
    dependencies: [
        .package(url: "https://github.com/pointfreeco/swift-parsing.git", from: "0.13.0"),
    ],
    targets: [
        .target(
            name: "test",
            dependencies: [
                .product(name: "Parsing", package: "swift-parsing"),
            ]
        ),
        .testTarget(name: "testTests", dependencies: ["test"]),
    ]
)

With this in place

docker run --rm -it -v $PWD:/host -w /host --entrypoint bash swift:5.9.1-jammy
swift build --build-tests

will trigger the build failure:

...
/host/.build/aarch64-unknown-linux-gnu/debug/CasePathsMacros.build/CasePathableMacro.swift.o:CasePathableMacro.swift.o:$s15CasePathsMacros12SelfRewriterCMf: error: undefined reference to '$s11SwiftSyntax0B8RewriterC13visitChildren33_F0C5D882E9301122F145EADC4573BFC8LLyxxAA0B8ProtocolRzlF'
<compiler-generated>:0: error: undefined reference to '$s19SwiftCompilerPlugin0bC0PAAE4mainyyKFZ'
/host/.build/aarch64-unknown-linux-gnu/debug/CasePathsMacros.build/Plugin.swift.o(.data.rel.ro+0x0): error: undefined reference to '$s17SwiftSyntaxMacros5MacroMp'
/host/.build/aarch64-unknown-linux-gnu/debug/CasePathsMacros.build/Plugin.swift.o(.data.rel.ro+0x20): error: undefined reference to '$s19SwiftCompilerPlugin0bC0Mp'
clang-13: error: linker command failed with exit code 1 (use -v to see invocation)
error: fatalError
[3/4] Linking testPackageTests.xctest
root@docker-desktop:/host# 

I'm at a loss what might trigger this. Some module that's referenced by default on macOS but needs an explicit import on Linux perhaps?

[finestructure]

Both swift-parsing and swift-case-paths individually run swift test on Linux in my testing. It's only in the context of using them as a dependency where the linker error occurs.

[stephencelis]

@finestructure I believe there are a few SPM bugs that cause swift test on packages that depend on SwiftSyntax to fail on non-Apple platforms. See sebsto/xcodeinstall#33 and the issues it links to. We're hopeful it'll be fixed in Swift 5.9.2, but have been kind of in limbo till then...

We're open to other ideas, but since this seems to be an Apple bug and not a bug in the library, I'm going to convert it to a discussion.

[stephencelis]

@finestructure Do you think the 5.9 failures I'm seeing here are related?

https://swiftpackageindex.com/pointfreeco/swift-composable-architecture/builds

[finestructure]

@stephencelis this is fixed now: SwiftPackageIndex/SwiftPackageIndex-Server#2761 (comment)

[finestructure]

Oh, that's new. I think it's a different problem though. If you go to the start of the logs you can see the problem:

/Users/builder/builds/TDmZkXJm/3/finestructure/swiftpackageindex-builder/spi-builder-workspace/.dependencies/checkouts/swift-dependencies/[email protected]:PACKAGE-TARGET:DependenciesMacrosPlugin: error: Target 'DependenciesMacrosPlugin' must be enabled before it can be used.

I'll need to see if there's a way to allow macros from the command line.

[finestructure]

Tracking this here: SwiftPackageIndex/SwiftPackageIndex-Server#2761

[finestructure]

Mmm, this may not be just a Linux problem. I've just started work on a new package on macOS. Here's the manifest:

// swift-tools-version: 5.9

import PackageDescription

let package = Package(
    name: "CanonicalPackageURLs",
    platforms: [.macOS(.v10_15)],
    products: [
        .library(
            name: "CanonicalPackageURLs",
            targets: ["CanonicalPackageURLs"]),
    ],
    dependencies: [
        .package(url: "https://github.com/pointfreeco/swift-parsing", from: "0.13.0")
    ],
    targets: [
        .target(
            name: "CanonicalPackageURLs",
            dependencies: [
                .product(name: "Parsing", package: "swift-parsing")
            ]
        ),
        .testTarget(name: "CanonicalPackageURLsTests", dependencies: ["CanonicalPackageURLs"]),
    ]
)

Running swift test fails here, too:

      static CasePathsMacros.CasePathableMacro.expansion<A, B where A: SwiftSyntax.DeclGroupSyntax, B: SwiftSyntaxMacros.MacroExpansionContext>(of: SwiftSyntax.AttributeSyntax, providingMembersOf: A, in: B) throws -> [SwiftSyntax.DeclSyntax] in CasePathableMacro.swift.o
      closure #2 (SwiftSyntax.EnumCaseElementSyntax) -> SwiftSyntax.DeclSyntax in static CasePathsMacros.CasePathableMacro.expansion<A, B where A: SwiftSyntax.DeclGroupSyntax, B: SwiftSyntaxMacros.MacroExpansionContext>(of: SwiftSyntax.AttributeSyntax, providingMembersOf: A, in: B) throws -> [SwiftSyntax.DeclSyntax] in CasePathableMacro.swift.o
  protocol descriptor for SwiftCompilerPlugin.CompilerPlugin, referenced from:
      l_got.$s19SwiftCompilerPlugin0bC0Mp in Plugin.swift.o
  static (extension in SwiftCompilerPlugin):SwiftCompilerPlugin.CompilerPlugin.main() throws -> (), referenced from:
      static CasePathsMacros.CasePathsPlugin.$main() throws -> () in Plugin.swift.o
clang: error: linker command failed with exit code 1 (use -v to see invocation)
[4/5] Linking CanonicalPackageURLsPackageTests
error: fatalError

[finestructure]

Pinning this to revision: "0.12.0" makes swift test work again.

[stephencelis]

@finestructure Yup it was an issue that affected the Swift command line but not Xcode, so both Linux and macOS were affected. Now that Swift 5.9.2 is out you should be able to upgrade, though!

[finestructure]

Ah, that's great - thanks Stephen!

[finestructure]

Swift 5.9.2 does indeed fix this SwiftPackageIndex/SwiftPackageIndex-Server#2755 🎉