Rendering does not work when Quarto document is stored at `/`

I have:

• searched the issue tracker for similar issues
• installed the latest version of Quarto CLI
• formatted my issue following the Bug Reports guide

Bug description

When a Quarto document is stored at e.g. /mermaid.qmd, command quarto render /mermaid.qmd hangs forever.

Steps to reproduce

On a Linux machine with Docker installed:

docker run --rm -ti glcr.b-data.ch/r/verse:4.5.3 bash

quarto install chrome-headless-shell

nano /mermaid.qmd

---
title: Test rendering mermaid to docx
format: docx
---


```{mermaid}
gantt
    section TODO
        Test rendering mermaid: 2025-03-12, 30d
```

quarto render /mermaid.qmd

Cross reference:

• https://github.com/quarto-dev/quarto-cli/issues/10961#issuecomment-4110269299

Actual behavior

hangs

Expected behavior

pandoc 
  to: docx
  output-file: mermaid.docx
  default-image-extension: png
  variables: {}
  
metadata
  engines:
    - path: /opt/quarto/share/extension-subtrees/julia-engine/_extensions/julia-engine/julia-engine.js
  title: Test rendering mermaid to docx
  
Output created: mermaid.docx

Your environment

• Container: glcr.b-data.ch/r/verse:4.5.3

Quarto check output

Quarto 1.9.36
[✓] Checking environment information...
      Quarto cache location: /root/.cache/quarto
[✓] Checking versions of quarto binary dependencies...
      Pandoc version 3.8.3: OK
      Dart Sass version 1.87.0: OK
      Deno version 2.4.5: OK
      Typst version 0.14.2: OK
[✓] Checking versions of quarto dependencies......OK
[✓] Checking Quarto installation......OK
      Version: 1.9.36
      Path: /opt/quarto/bin

[✓] Checking tools....................OK
      TinyTeX: (external install)
      Chromium: (not installed)
      Chrome Headless Shell: (not installed)
      VeraPDF: (not installed)

[✓] Checking LaTeX....................OK
      Using: Installation From Path
      Path: /opt/TinyTeX/bin/linux
      Version: 2026

[✓] Checking Chrome Headless....................OK
      Chrome:  (not detected)

[✓] Checking basic markdown render....OK

[✓] Checking R installation...........OK
      Version: 4.5.3
      Path: /usr/local/lib/R
      LibPaths:
        - /usr/local/lib/R/site-library
        - /usr/local/lib/R/library
      knitr: 1.51
      rmarkdown: 2.30

[✓] Checking Knitr engine render......OK

[✓] Checking Python 3 installation....OK
      Version: 3.13.11
      Path: /usr/local/bin/python3
      Jupyter: (None)

      Jupyter is not available in this Python installation.
      Install with python3 -m pip install jupyter

[✓] Checking Julia installation...