Curating a module under a technology root causes the sidebar to not show Objective-C symbols

[steviki]

Description

When listing a module under a topics group in a technology root and supporting both Objective-C and Swift, the sidebar (and search) still only shows the Swift symbols even when switching the language to Objective-C.

When removing the technology root, this works as expected, and the symbols in the sidebar switch correctly to Objective-C names when changing the language.

Even adding @SupportedLanguage directives for both swift and objc doesn't fix this behavior.

Checklist

• If possible, I've reproduced the issue using the main branch of this package.
• This issue hasn't been addressed in an existing GitHub issue.

Expected Behavior

Switching the language to Objective-C should show the Objective-C symbols in the sidebar.

Actual behavior

Switching the language to Objective-C shows the Swift symbols in the sidebar.

Steps To Reproduce

This can be reproduced with the following project: SlothFramework.zip

This project contains a Swift file with a class that has a different name in Objective-C.

This project also contains a documentation catalog including a technology root page listing the framework this project produces in its topics group.

1. From the unzipped project directory run the following command (make sure to update the path to the docc binary).

export DOCC_HTML_DIR="$(dirname $(xcrun --find docc))/../share/docc/render" && xcodebuild docbuild -project SlothFramework.xcodeproj -scheme SlothFramework -derivedDataPath docbuild-deriveddata -destination 'generic/platform=iOS' && ../swift-docc/.build/arm64-apple-macosx/debug/docc preview SlothFramework/SlothFramework.docc --fallback-bundle-version 1 --output-dir Sloth.doccarchive --additional-symbol-graph-dir docbuild-deriveddata/Build/Intermediates.noindex/SlothFramework.build/Debug-iphoneos/SlothFramework.build/symbol-graph

2. Open the preview documentation in a browser and switch the language to Objective-C.
3. See that the sidebar still shows the Swift symbols.

Swift-DocC Version Information

3e0c8e2

Swift Compiler Version Information

swift-driver version: 1.90.11.1 Apple Swift version 5.10 (swiftlang-5.10.0.13 clang-1500.3.9.4)
Target: arm64-apple-macosx14.0