I'm trying to use a web assembly (wasm) module, but wasm modules must be served with the content type application/wasm, and when running bundle exec jekyll serve to test the site locally, they are instead served with the content type application/octet-stream used for unrecognized file types. As far as I can tell, this was fixed upstream in Webrick back in 2019, but the github-pages gem is using an outdated version of jekyll which is in turn using an outdated version of webrick that doesn't have the fix.

I tried pushing my changes to github and wasm modules are served with the correct MIME type on a live github pages site. I'm not sure why it works live and is broken locally when the entire point of the github-pages gem is to replicate the same configuration for local testing in order to avoid such issues, but it seems like this can at least be easily fixed by updating the dependencies of the gem.