Issue with node-fetch

[lukebennett88]

I have a Remix app as part of a turborepo monorepo and deployed on Vercel.
It's pretty simple at this point, basically just the turborepo-vercel examples with a few personal preferences.
The source is here:
https://github.com/lukebennett88/remix-turborepo-vercel

I've deployed this to Vercel, and the app is loading just fine:
https://remix-turborepo-vercel.vercel.app/

I then added some code to build pages from Sanity (see diff here: https://github.com/lukebennett88/remix-turborepo-vercel/tree/add-sanity).

This works fine locally, but when I deploy I get the following error:

TypeError: this.fetcher is not a function
    at PicoSanity.fetch (/var/task/output/server/pages/api/index.js:120959:15)
    at loader (/var/task/output/server/pages/api/index.js:124500:35)
    at callRouteLoader (/var/task/output/server/pages/api/index.js:107527:20)
    at /var/task/output/server/pages/api/index.js:112115:108
    at Array.map (<anonymous>)
    at renderDocumentRequest (/var/task/output/server/pages/api/index.js:112115:67)
    at requestHandler (/var/task/output/server/pages/api/index.js:111900:26)
    at /var/task/output/server/pages/api/index.js:113258:26
    at Server.<anonymous> (/var/task/output/server/pages/api/___vc/__helpers.js:813:19)
    at Server.emit (events.js:400:28)

If I take a look at the source for PicoSanity I can see that node-fetch is a dependency which is passed in as the second param of the Client function, and inside of the Client function I can confirm that the second param of the function is referred to as "fetcher", so it looks to me like node-fetch is not getting bundled correctly (maybe I need to do something with Rollup?).

The other thing I should mention is that the diff I showed above was squashed and merged from another branch that I have since (foolishly) deleted. The deleted branch is where the message above comes from. For some reason the deploy preview from squashing and merging the commits 404s instead of showing the error boundary. If I look at the build in Vercel it seems the that /build folder doesn't exist, only the /api folder. The code is exactly the same, so I can't explain why this would be the case.