`builtArtifact` empty when building a target from dependencies

[supersonicbyte]

Is it reproducible with SwiftPM command-line tools: swift build, swift test, swift package etc?

• Confirmed reproduction steps with SwiftPM CLI. The description text must include reproduction steps with either of command-line SwiftPM commands, swift build, swift test, swift package etc.

Description

I believe that a38e1d6 introduced a regression where when building a product from a dependency will return empty build artifacts.

Here is an example repo: https://github.com/supersonicbyte/plugin-package-manager-build

When we try to invoke the command plugin inside the LocalPackages/Client directory built artifacts will be [] after this commit. On versions before this commit everything works as expected.

Expected behavior

The build artifcats not to be empty.

Actual behavior

The build artifact array is empty.

Steps to reproduce

1. Clone repo: https://github.com/supersonicbyte/plugin-package-manager-build
2. cd LocalPackages/Client
3. swift package plugin_package_manager_build

Swift Package Manager version/commit hash

No response

Swift & OS version (output of swift --version ; uname -a)

swift-driver version: 1.120.5 Apple Swift version 6.1.2 (swiftlang-6.1.2.1.2 clang-1700.0.13.5)
Target: arm64-apple-macosx15.0
Darwin Mac 24.6.0 Darwin Kernel Version 24.6.0: Mon Jul 14 11:28:30 PDT 2025; root:xnu-11417.140.69~1/RELEASE_ARM64_T6030 arm64

[dschaefer2]

@cmcgee1024 any thoughts there?

[supersonicbyte]

Maybe I wasn't clear enough in the description. To rephrase a bit, a command plugin which invokes the PackageManager API to build a module, e.g (from the repo):

   let parameters = PackageManager.BuildParameters(configuration: .release)
   let buildResult = try packageManager.build(.target("Core"), parameters: parameters)

The buildResults will be empty in every version after the commit I highlighted when invoked on a package that has this plugin as a dependency. That's because the code that populates the buildResult traverses only modules from the root package and it cannot found the Core module which is part of the command plugin package.

I made a PR which fixes this by traversing all packages in the resolved graph, so the Core module is reachable.

[supersonicbyte]

I think we can close this issue since it got resolved with 7046c68.