windows + ruby-head fails because it's an old build:
ruby 4.0.0dev (2025-11-30 master bae06ce22c) +PRISM [x64-mingw-ucrt]

What's weird is at https://github.com/oneclick/rubyinstaller2/releases/tag/rubyinstaller-head I see files updated 1 hour ago.
So files were uploaded but they are of an old build?
cc @larskanis

The build is two part: compiling in https://github.com/oneclick/rubyinstaller2-packages/actions and packaging in https://github.com/oneclick/rubyinstaller2/actions . The compile action fails since end of November but I didn't fix it right now. I'll check today.

The rubyinstaller-head versions are updated now: https://github.com/oneclick/rubyinstaller2/releases/tag/rubyinstaller-head
Sorry for the inconvenience!

Thank you for your quick fix and all your work for RubyInstaller, etc!