Goals

1. Environment Variable docs are misleading

Non-goals

None

Background

The docs state:

For example, a lint task probably doesn't need to miss cache when the value of API_KEY changes, but a build task likely should.

From my understanding, API_KEY shouldn't result in miss cache for build task. When a Next.js app or Express/Fastify app is built with esbuild for example and I reference an environment variable like process.env.API_KEY the API_KEY is not bundled into the output. You have to specify --define or in Next.js prefixed env var with NEXT_PUBLIC or do something special for the env var to be bundled into output.

Therefore, I think that docs are misleading. From my understanding, really the only env vars that need to result in cache miss are the framework inference ones (thank you for making that easy!).

Proposal

My recommendation is to change:

Turborepo needs to be aware of your environment variables to account for changes in application behavior.

to

Turborepo needs to be aware of your environment variables that are bundled into your app's build to account for changes in application behavior.

and change the example API_KEY to NEXT_PUBLIC_API_KEY.

Additionally, I think the first question is not correct:

Are my environment variables accounted for in the task hash?

It should be: Which environment variables are included in my app's builds such that I need to tell turbo to include them in the task hash?