double `documentation` & changed URL for viewing static hosted DocC Archives with Swift 6.2

[heckj]

Description

Using the docc that's included with Swift 6.2 (through Xcode 26.1 beta 2), I was setting up a new DocC catalog for static hosting using GitHub pages.

The command I used:

xcrun docc convert \
  ecosystem/EcosystemTools.docc \
  --enable-mentioned-in \
  --enable-experimental-external-link-support \
  --hosting-base-path jheck2/prototype \
  -o docs

The catalog in question is an article-only catalog

Given the naming and previous experience, I expected the final URL to be:

https://github-enterprise.whatever/jheck2/prototype/documentation/ecosystemtools/

But that failed with a 404 response, and digging around in the archive output, the new URL structure appears to be:

https://github-enterprise.whatever/jheck2/prototype/documentation/documentation/

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

Based on previous output, I expected the final URL segment to be the name of the archive.

Actual behavior

The URL structure included a repeated documentation twice in the path, and no name of the archive

Steps To Reproduce

1. create a new, emtpy docc catalog
2. use docc convert to generate an archive
3. inspect the archive, noting the documentation directory, which is the primary landing point for the HTML requests coming in with static hosting.

build.doccarchive
├── css
│   ├── 39.cc2d61d1.css
│   ├── 989.4f123103.css
│   ├── documentation-topic.b031fba4.css
│   ├── index.d0b63544.css
│   ├── topic.59e2bdb7.css
│   └── tutorials-overview.9c2b2457.css
├── data
│   └── documentation
│       └── documentation.json
├── developer-og-twitter.jpg
├── developer-og.jpg
├── documentation
│   └── documentation
│       └── index.html
├── downloads
│   └── Example
├── favicon.ico
├── favicon.svg
├── images
│   └── Example
├── img
│   ├── added-icon.832a5d2c.svg
│   ├── deprecated-icon.7bf1740a.svg
│   └── modified-icon.efb2697d.svg
├── index
│   └── index.json
├── index.html
├── js
│   ├── 104.13ecc36d.js
│   ├── 337.274a8ccc.js
│   ├── 39.06467a79.js
│   ├── 842.b02efbfb.js
│   ├── chunk-vendors.bdb7cbba.js
│   ├── documentation-topic.eef64d7d.js
│   ├── highlight-js-bash-js.702f0c5c.js
│   ├── highlight-js-c-js.063069d3.js
│   ├── highlight-js-cpp-js.458a9ae4.js
│   ├── highlight-js-css-js.bfc4251f.js
│   ├── highlight-js-custom-markdown.78c9f6ed.js
│   ├── highlight-js-custom-swift.738731d1.js
│   ├── highlight-js-diff-js.4db9a783.js
│   ├── highlight-js-http-js.f78e83c2.js
│   ├── highlight-js-java-js.4fe21e94.js
│   ├── highlight-js-javascript-js.dfc9d16d.js
│   ├── highlight-js-json-js.2a1856ba.js
│   ├── highlight-js-llvm-js.26121771.js
│   ├── highlight-js-markdown-js.a2f456af.js
│   ├── highlight-js-objectivec-js.74dea052.js
│   ├── highlight-js-perl-js.da6eda82.js
│   ├── highlight-js-php-js.c458ffa4.js
│   ├── highlight-js-python-js.60354774.js
│   ├── highlight-js-ruby-js.7272231f.js
│   ├── highlight-js-scss-js.adcd11a2.js
│   ├── highlight-js-shell-js.0ad5b20f.js
│   ├── highlight-js-swift-js.bdd5bff5.js
│   ├── highlight-js-xml-js.0d78f903.js
│   ├── index.5b6366e8.js
│   ├── topic.c7f55345.js
│   └── tutorials-overview.9144a669.js
├── metadata.json
└── videos
    └── Example

Swift-DocC Version Information

6.2.0

Swift Compiler Version Information

swift-driver version: 1.127.14.1 Apple Swift version 6.2.1 (swiftlang-6.2.1.4.2 clang-1700.4.4.1)
Target: arm64-apple-macosx26.0

[heckj]

Example project is available at https://github.com/heckj/article-only-docc

git clone https://github.com/heckj/article-only-docc
cd article-only-docc
xcrun docc convert Example.docc -o example.doccarchive

resulting tree:

tree example.doccarchive
example.doccarchive
├── css
│   ├── 39.cc2d61d1.css
│   ├── 989.4f123103.css
│   ├── documentation-topic.b031fba4.css
│   ├── index.d0b63544.css
│   ├── topic.59e2bdb7.css
│   └── tutorials-overview.9c2b2457.css
├── data
│   └── documentation
│       ├── documentation.json
│       └── example
│           └── example-article.json
├── developer-og-twitter.jpg
├── developer-og.jpg
├── documentation
│   ├── documentation
│   │   └── index.html
│   └── example
│       └── example-article
│           └── index.html
├── downloads
│   └── Example
├── favicon.ico
├── favicon.svg
├── images
│   └── Example
├── img
│   ├── added-icon.832a5d2c.svg
│   ├── deprecated-icon.7bf1740a.svg
│   └── modified-icon.efb2697d.svg
├── index
│   └── index.json
├── index.html
├── js
│   ├── 104.13ecc36d.js
│   ├── 337.274a8ccc.js
│   ├── 39.06467a79.js
│   ├── 842.b02efbfb.js
│   ├── chunk-vendors.bdb7cbba.js
│   ├── documentation-topic.eef64d7d.js
│   ├── highlight-js-bash-js.702f0c5c.js
│   ├── highlight-js-c-js.063069d3.js
│   ├── highlight-js-cpp-js.458a9ae4.js
│   ├── highlight-js-css-js.bfc4251f.js
│   ├── highlight-js-custom-markdown.78c9f6ed.js
│   ├── highlight-js-custom-swift.738731d1.js
│   ├── highlight-js-diff-js.4db9a783.js
│   ├── highlight-js-http-js.f78e83c2.js
│   ├── highlight-js-java-js.4fe21e94.js
│   ├── highlight-js-javascript-js.dfc9d16d.js
│   ├── highlight-js-json-js.2a1856ba.js
│   ├── highlight-js-llvm-js.26121771.js
│   ├── highlight-js-markdown-js.a2f456af.js
│   ├── highlight-js-objectivec-js.74dea052.js
│   ├── highlight-js-perl-js.da6eda82.js
│   ├── highlight-js-php-js.c458ffa4.js
│   ├── highlight-js-python-js.60354774.js
│   ├── highlight-js-ruby-js.7272231f.js
│   ├── highlight-js-scss-js.adcd11a2.js
│   ├── highlight-js-shell-js.0ad5b20f.js
│   ├── highlight-js-swift-js.bdd5bff5.js
│   ├── highlight-js-xml-js.0d78f903.js
│   ├── index.5b6366e8.js
│   ├── topic.c7f55345.js
│   └── tutorials-overview.9144a669.js
├── metadata.json
└── videos
    └── Example