Attempting to install the extension in vscodium (even using the exact extension name) brings up anything but the extension. Probably a simple fix but unsure as I don't dabble in extensions.

Edit: it seems I can just ask you to publish the extension to open-vsx.org
https://github.com/VSCodium/vscodium/blob/master/docs/extensions.md#marketplace

Edit 2: A "fix" before the issue is closed: you can download the extension's .vsix from here and install it with codium --install-extension /path/to/jacobcassidy.css-nesting-syntax-highlighting-0.4.0.vsix. Replace 0.4.0 with the latest version number in the url and command!

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