BUG: problem with default export / import in some cases

Quick checklist

• I am using the latest version of Snowpack and all plugins.

What package manager are you using?

yarn

What operating system are you using?

macOS

Describe the bug

Possibly related to: #3926

Using all the latest:

• react (18)
• @mui (v5)
• snowpack (3.8.x)

I am unable to actually use any MUI features due to a runtime error where an object is called like a function.

This appears to happen because one of MUIs dependencies (@emotion) is trying to default export the function createCache but somewhere in the process this is messed up and we get createCache = {default: f} rather than the expected createCache = f

I think the @mui and @emotion code looks good, so I am suspecting snowpack or some weird shenanigans here as the culprit. Hoping someone will be more familiar and able to at least give / on this theory.

Steps to reproduce

Clone my minimal example (below) then yarn install && yarn start You should see the same error...

Link to minimal reproducible example (optional)

https://github.com/oclyke-zucchini/snowpack-mui-emotion-createCache-not-function