buildTool Plugin: Multiple commands produce

Development Package Manager
1

I created a build tool plugin to generate symbols from an asset catalog.
The plugin calls an executable target that generates a Colors.swift file.

The plugin works as expected.

My app target (the one that imports the package containing the plugin) has an iOS and a Watch App target, meaning the executable is called twice when compiling the app.

The error looks like this:

Multiple commands produce '/Users/g1intlv/Library/Developer/Xcode/DerivedData/Stage-asmtpprdyfhrcubtcapnpsvqjlkf/SourcePackages/plugins/stage.output/StageDesignSystem/GenerateColors/Colors.swift'

This is my plugin declaration:

        .plugin(
            name: "GenerateColors",
            capability: .buildTool(),
            dependencies: ["GenerateColorsExec"]
        ),
        .executableTarget(
            name: "GenerateColorsExec",
            path: "Plugins/GenerateColorsExec"
        ),

Is this expected? A workaround could be to exclude the Watch App in the executable. Can I do that using some swift setting? I.e.

swiftSettings: [SwiftSetting]
2

I’ve had that problem twice so far without ever finding a workaround. I haven’t checked if it’s been fixed on Xcode 16.

There’s a couple open threads but the conclusion is mostly that SwiftPM won’t fix it because it only happens with Xcode.

3

Did we found any workaround for this @gmoraleda @Lancelotbronner ?

4

Unfortunately not, I had to abandon those projects :(

5

Same here.
Ended up surrendering and using a command plugin instead, to manually generate the output file :pensive: