Item with the same name already exists error when merging doc archives

[cmcgee1024]

Description

I'm trying to merge all of the documentation archives generated from symbol graphs of different modules in SwiftPM. However, the merge fails on repeated errors like the following:

Error: “packagecollections” couldn’t be copied to “documentation” because an item with the same name already exists.

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

It's expected that either the merge completes successfully, or an actionable message is produced so that it can be fixed.

Actual behavior

Instead, it produces a non-actionable error.

Steps To Reproduce

Extract this archive with the DocC archives generated from the modules in SwiftPM:

docc-archives.tar.gz

With a Swift 6.2 toolchain, run the merge.sh script to merge all of the DocC archives into a single archive:

./merge.sh

Swift-DocC Version Information

6.2.0

Swift Compiler Version Information

Apple Swift version 6.2 (swift-6.2-RELEASE)
Target: arm64-apple-macosx26.0
Build config: +assertions

[heckj]

I think this might be the same as #1322