Fix NEXT_PUBLIC_ environment variables in cache

- Use dynamic lookup for `NEXT_PUBLIC_VERCEL_URL` to avoid inlining
- Add `NEXT_PUBLIC_SANITY_*` to Turborepo `pipeline.build.env` cache key

apps/site/src/lib/utils/api.ts

@@ -2,7 +2,10 @@ import axios from "axios";
 import { cookies } from "next/headers";
 
 const LOCAL_API_URL = "http://localhost:8000";
-const SERVER_HOST = process.env.NEXT_PUBLIC_VERCEL_URL;
+// Important: we need to do a dynamic lookup since otherwise the environment variable
+// will be inlined during build and cause faulty caching issues (see #290)
+const varName = "NEXT_PUBLIC_VERCEL_URL";
+const SERVER_HOST = process.env[varName];
 
 // The Vercel Serverless Function for the API lives outside the scope of Next.js
 // so the publicly deployed URL must be used instead of a rewrite

apps/site/turbo.json

@@ -2,6 +2,7 @@
 	"extends": ["//"],
 	"pipeline": {
 		"build": {
+			"env": ["NEXT_PUBLIC_SANITY_*"],
 			"inputs": [
 				"src/**",
 				"public/**",