Jekyll on Windows 11 for GitHub Pages preview

Differences in Jekyll experiences on different Windows versions
are mostly about Ruby and Jekyll evolution and breaking changes.
Ruby installation has become more trouble-free, without hangs and need for retries.
Meanwhile, Jekyll functionality on Windows seems to have regressed:

<details> seemingly are no longer supported in markdown

jekyll new markdown defaults to blog-specific format

Gemfile configured for page appearances to match GitHub Pages theme
      causes GitHub Pages deployment action to timeout:

	$ diff Gemfile ../site
	5c5
	< gem 'github-pages'                            # Windows Jekyll: no theme
	---
	> gem 'github-pages', group: :jekyll_plugins    # GitHub Pages Action times out

ignores markdown files lacking front matter starting on the first line

This last issue differs between Jekyll on Windows and GitHub's Jekyll docker.
Fortunately, empty front matter suffices to enable markdown processing;
default title is overridden by a markdown ### heading immediately below front matter.

---
---
### Custom Title

Over 60 markdown files in my GitHub Pages needing editting for these issues...

Trivial changes typically required over 5 minutes for GitHub to process.

Starting over, I would completely stick to HTML for GitHub Pages.

Work-arounds to match themed pages served on Windows vs GitHub Pages

• Spun out separate projects to reduce GitHub Pages commit times:
  static (folders without markdown), microscope, Arduino-Blue-Pill.
• Deleted Gemfile.lock, pushed to GitHub, then added to .gitignore.
  GitHub Pages builds fine without it, the major source of dependabot issues.
• Likewise, added _site/ to .gitignore.
• On Windows, unset JEKYLL_GITHUB_TOKEN before bundle exec jekyll serve
  to avoid github-pages issues.
• Serve local Jekyll from folder site/, which builds site/_site/
  from ../blekenbleu.github.io/, using custom _config.yml:

  theme: jekyll-theme-tactile
  repository: blekenbleu/blekenbleu.github.io
  source: ../blekenbleu.github.io/

• In site/_site/, link:
  microscope _site/ build folder, static/ and Arduino-Blue-Pill/docs/ folders.
  bundle exec jekyll serve --incremental running in site/
  detects changes in neither microscope nor Arduino-Blue-Pill;
  each requires bundle exec jekyll build to update their _site/ folder.
  
  
• Regenerate and serve blekenbleu.github.io/ (markdown) changes from site/ folder,
  while changes to content linked in site/_site/ are served,
  but transparent to its Jekyll regeneration.
  
  Linking needs repeating whenever site/_site/ gets regenerated;
  links.bat does that:

  cd _site
  mklink /d Arduino-Blue-Pill ..\..\..\Arduino\Blue-Pill\docs
  mklink /d microscope ..\..\microscope\_site
  mklink /d static ..\..\static

github-pages issues

To apply themes, Windows Jekyl requires in Gemfile:
gem 'github-pages', group: :jekyll_plugins
Beyond that, with JEKYLL_GITHUB_TOKEN set, bundle exec jekyll serve fails with:

Liquid Exception: The GitHub API credentials you provided aren't valid. in /_layouts/default.html

$ bundle exec github-pages health-check
 (LoadError)4/lib/ruby/gems/3.2.0/gems/ffi-1.15.5/lib/ffi/library.rb:145:in `block in ffi_lib':
 Could not open library 'libcurl': The specified module could not be found.
.
Could not open library 'libcurl.dll': The specified module could not be found.
.
Could not open library 'libcurl.so.4': The specified module could not be found.
.
Could not open library 'libcurl.so.4.dll': The specified module could not be found.

...FWIW, there is no /_layouts/default.html.

Installed curl, which did not help:

$ pacman -Sy mingw-w64-x86_64-curl
$ find /f -name curl.h -print
/f/Ruby32-x64/msys64/mingw64/include/curl/curl.h
$ gem install curb --platform=ruby -- --with-curl-lib="F:/Ruby32-x64/msys64/mingw64/lib"
     --with-curl-include="F:/Ruby32-x64/msys64/mingw64/include"
Temporarily enhancing PATH for MSYS/MINGW...
Building native extensions with: '--with-curl-lib=F:/Ruby32-x64/msys64/mingw64/lib
     --with-curl-include=F:/Ruby32-x64/msys64/mingw64/include'
This could take a while...
Successfully installed curb-1.0.5
Parsing documentation for curb-1.0.5
Installing ri documentation for curb-1.0.5
Done installing documentation for curb after 0 seconds
1 gem installed 

... bundle exec github-pages health-check still fails the same way.

Ruby updates

While Ruby gems can be updated, Ruby itself as installed by RubyInstaller cannot.
Ruby is used here only for Jekyll, but its bundled MSYS2 gets used extensively,
with several packages added.  Before replacing Ruby,
run MSYS2 package manager to document its current package list:

pacman -Q > /d/oldMSYS2.txt
.. then compare with new MSYS2 for determining packages to add.
Of course, any MSYS2 home/user folder customizations should also be ported.