Nested SystemCapabilities target attribute is serialized as a quoted Swift dictionary

[gigq]

XcodeGen version

Burned first recorded this output on 2026-07-14, when 2.45.4 was the current release. The 2.46.0 source still passes nested target attributes through ProjectAttribute(any:); I am adding exact version output to the downstream CI reproduction and will comment with that result.

Minimal project spec

name: CapabilityRepro
targets:
  CapabilityRepro:
    type: application
    platform: iOS
    attributes:
      SystemCapabilities:
        com.apple.HealthKit:
          enabled: 1

Actual generated project.pbxproj

SystemCapabilities = "[\"com.apple.HealthKit\": [\"enabled\": 1]]";

The nested dictionary is emitted as a quoted Swift dictionary description. Xcode expects SystemCapabilities to be a PBX dictionary, so a downstream post-generation hook currently has to replace it.

Expected output

SystemCapabilities = {
    com.apple.HealthKit = {
        enabled = 1;
    };
};

Downstream context

The tracked workaround is in codesmithing-dev/Burned#67. It validates the exact malformed shape before rewriting it and will deliberately fail once XcodeGen emits the native PBX dictionary so the hook can be retired.

[gigq]

Downstream Apple CI has now recorded the exact generator version: XcodeGen 2.45.4 reproduced the quoted nested SystemCapabilities shape, and the exact-shape normalization/drift test passed. The 2.46.0 source inspection noted above is not yet an executable reproduction.

[sergeyospanov]

Hi! I'd like to work on this.

I reproduced the conversion path in the current master: nested target attributes reach ProjectAttribute(any:), which currently stringifies dictionaries even though XcodeProj supports attributeDictionary. I plan to add a focused generator regression for the SystemCapabilities shape above, implement the narrow dictionary conversion, and run the focused and full SwiftPM test suites before opening a PR.