Can't load extension because of mimetype mismatch

JupyterLab extensions
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1

I’m trying to load an extension that I’ve developed locally, but when I launch JupyterLab and open a notebook I’m getting this error:

The resource from “http://localhost:8888/lab/extensions/jupyterlab-ihaskell/static/remoteEntry-9c60627a05d7fcc32ccf.js” was blocked due to MIME type (“text/html”) mismatch (X-Content-Type-Options: nosniff).

The extension seems to correctly show up in the extension manager and this workflow was fine in previous versions. Is there something I’m missing?

2

My current theory is that my extension is not being loaded correctly, but I’m setting JUPYTER_PATH which worked like I expected in previous versions. Has something changed here with JupyterLab 4?