SPM dependency symbols duplicated in test target

[armcknight]

I have a project that uses SPM and CocoaPods. Incidentally, pod install fails unless I force link: true for any SPM dependencies for my targets. So I have a static lib target with an SPM dependency with link: true, and a test target (with no test host) that exercises that static lib target. The lib target builds fine, but the test target fails due to all the SPM dependency's symbols being duplicated. There is no visible, direct linkage between the test target and the SPM dependency, other than through the static lib.

Removing link: true avoids the symbol duplication but as stated, I cannot remove it or pod install will subsequently fail.

Attached is a sample project demonstrating the setup.

Seems similar to https://github.com/yonaskolb/XcodeGen/issues/748 but since this involves test targets and that was an app target, this seemed different.

spm-unit-test-duplicate-symbol-example-xcodegen.zip

The xcodegen spec should read:

name: spm-unit-test-duplicate-symbol-example-xcodegen
packages:
  RegularExpressionDecoder:
    url: https://github.com/Flight-School/RegularExpressionDecoder
    from: 0.1.0
schemes:
  lib:
    build:
      targets:
          lib: all
  tests:
    build:
      targets:
          tests: test
    test:
      targets: [tests]
targets:
  lib:
    type: library.static
    sources:
      - path: lib
    platform: macOS
    dependencies:
      - package: RegularExpressionDecoder
        link: true
    deploymentTarget: 10.15
    scheme:
      testTargets:
        - tests
  tests:
    type: bundle.unit-test
    platform: macOS
    deploymentTarget: 10.15
    sources:
      - path: tests
    dependencies:
      - target: lib