I have a build which is for a decently basic Nest.js app with Node and TypeScript. I'm using yarn 4.1.1 as a package manager, and i've recently found something really strange.

Modern yarn projects don't support caching by default within nixpacks, so I tried adding cacheDirectories to my package.json to cache .yarn/cache in my project.

After adding it, the build time went from ~20 seconds to ~5x that. Not only that, but the publish time seems to roughly 10x what it was before (lasting 264 (!) seconds). I'm not sure exactly what's going on but it's not good and I figured I'd ask about it here.