Website sidebar auto generation renders differently on Windows vs Linux

Bug description

Description

Using the sidebar auto generation feature, I get different results between Windows and Linux. I have two nested folder structures with index.qmd files along content files for each section. On Windows, the index pages are added to the sidebar as expected, while on Linux, they are omitted.

Side-by-side comparison

Version and OS info

Using Quarto v1.2.90 on

• Windows 11 Pro 21H2 build 22000.856
• Ubuntu 20.04.3 LTS through WSL2
• GitHub Actions ubuntu-latest using the official quarto-setup action

Minimal, fully reproducible example

Directory structure:

.
├── _quarto.yml
├── home.qmd
└── section1
    ├── index.qmd
    ├── page1.qmd
    └── page2.qmd

_quarto.yml

project:
  type: website

website:
  sidebar:
    contents:
      - text: "Home"
        file: home.qmd
      - "---"
      - auto: section1

home.qmd

# Home
Homepage content

section1/index.qmd

# Section 1
Section 1 content

section1/page1.qmd

# Page 1
content page 1

section1/page2.qmd

# Page 2
content page 2

Checklist

• Please include a minimal, fully reproducible example in a single .qmd file? Please provide the whole file rather than the snippet you believe is causing the issue.
• Please format your issue so it is easier for us to read the bug report.
• Please document the RStudio IDE version you're running (if applicable), by providing the value displayed in the "About RStudio" main menu dialog?
• Please document the operating system you're running. If on Linux, please provide the specific distribution.

Start with the reproducible website described in _quarto.yml, using home.qmd and section1/index.qmd, page1.qmd, and page2.qmd. Build it on Windows and Linux, compare the generated sidebars, and trace the auto: section1 path handling until the index page is consistently included.