We recently pushed a change that updates Vitepress (used for the Codex docs site) to `v1.0.0-alpha.47`. It looks like this latest version of Vitepress requires Node `v16.6.0` or greater due to use of `Array.prototype.at` in its internals (parsing filenames). See the compatibility table for this method here: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/at#browser_compatibility
PatchDemo is still running Node 14. This means that all attempts to build Codex inside of a PatchDemo instance now fail with the following error:
```
build error:
TypeError: filename.split(...).at is not a function
```
There are also a lot of "unsupported engine" warnings in the console output.
### Short-term solution
We should revert the Vitepress update in our code to preserve PatchDemo functionality.
### Long-term solution
PatchDemo should be updated to use Node LTS version 16.
### Alternate solution
Looks like Vitepress fixed this problem themselves upstream, and it's been included in the alpha 48 release which came out yesterday. See https://github.com/vuejs/vitepress/commit/fd995906f61e5181ca8e1116dcd93eec65075056 (included in the latest release).