1.8.0 always outputs an error for swift package generate-manual (see reproduction), while it worked in 1.7.1 & earlier.

ArgumentParser version:
1.8.0

Swift version:
swift-driver version: 1.148.6 Apple Swift version 6.3.2 (swiftlang-6.3.2.1.108 clang-2100.1.1.101)
Target: arm64-apple-macosx26.0

Checklist

• If possible, I've reproduced the issue using the main branch of this package
• I've searched for existing GitHub issues

Steps to Reproduce

$ swift package generate-manual
…Fetching libraries…
Building for debugging...
[94/94] Applying generate-manual-tool
Build of product 'generate-manual' complete! (4.49s)
Building package in release mode...
Built package in release mode
Generating manual for mas...
error: Failed to create output directory: 'You don’t have permission to save the file “mas.docc” in the folder “mas”.'

I don't know if folder "mas" is for the package, product, or executableTarget, as they all have the same name for my SwiftPM project.

If you cannot reproduce yourself, my project is at https://github.com/mas-cli/mas. You can update swift-argument-parser to 1.8.0 in Package.swift & update the one line of code that must be updated to avoid a build error with 1.8.0.

Expected behavior

No error.

Actual behavior

Error.