Version switcher config missing from some pages when using sphinx-tabs

[krivard]

Hi, I'm trying to configure the version switcher, but it's only behaving properly on some pages. When I deactivate the sphinx-tabs extension, all problems vanish. The reason I'm reporting it here instead of there is because I chased the problem to missing DOCUMENTATION_OPTIONS settings, which are controlled here. If it turns out that the pydata theme is trying to write DOCUMENTATION_OPTIONS to index but sphinx-tabs is somehow blocking or overwriting, then I'll go and yell over there :)

What I expected:

• version switcher should populate on all pages for which it is configured in html_theme_options

What I found:

• version switcher appears but does not populate on the index/home/root page
• version switch does populate correctly on search results page, the generated index/sitemap, and a mystery subset of other pages in a more complex environment than the one I've included below. Oddly it doesn't seem to correspond to whether or not a sphinx-tabs tab appears on the page.
• version switcher misbehavior exactly corresponds to whether or not the page includes DOCUMENTATION_OPTIONS settings in the built html

To reproduce:

1. Set up a blank sphinx site with the following conf.py:

"""Configuration file for the Sphinx documentation builder."""
project = "version switcher bug"
extensions = [
    "sphinx_tabs.tabs",
]

html_theme = "pydata_sphinx_theme"

html_theme_options = {
    "switcher": {
        "json_url": "https://pydata-sphinx-theme.readthedocs.io/en/latest/_static/switcher.json",
        "version_match": "dev"
    },
   "navbar_start": ["navbar-logo", "version-switcher"],
}

2. Build the site and host locally by running python -m http.server --bind 127.0.0.1 8080 from the html directory
3. Browse to http://127.0.0.1:8080/index.html
   • Observe: version switcher says "Choose version" and no versions are available in the dropdown
4. Use the search bar to search any query and view the search results page
   • Observe: version switcher says "dev" and many version are available in the dropdown
5. Confirm cause of misbehavior by running find [build_directory] -name "*.html" -exec grep DOCUMENTATION_OPTIONS {} +
   • Observe: DOCUMENTATION_OPTIONS is not set in index.html, only in search.html and genindex.html
6. Remove the sphinx-tabs extension and rebuild the site
   • Observe: version switcher populates correctly on all pages and DOCUMENTATION_OPTIONS appears in index.html as it should.

[melissawm]

I can't reproduce unfortunately - with your setup above and looking at the built pages on a server or just as static files, the switcher works correctly: