Error with docker image from standalone output

[moy2010]

I have recently started playing with a new app powered by next-firebase-auth, but I stumbled upon an error that only occurs when generating the docker image (a.k.a. everything works as expected when running in dev mode):

error TypeError [ERR_INVALID_ARG_TYPE]: The "key" argument must be of type string or an instance of ArrayBuffer, Buffer, TypedArray, DataView, KeyObject, or CryptoKey. Received undefined
     at new NodeError (node:internal/errors:406:5)
     at prepareSecretKey (node:internal/crypto/keys:596:11)
     at new Hmac (node:internal/crypto/hash:130:9)
     at Object.createHmac (node:crypto:170:10)
     at sign (/app/node_modules/.pnpm/[email protected]/node_modules/keygrip/index.js:23:8)
     at Keygrip.sign (/app/node_modules/.pnpm/[email protected]/node_modules/keygrip/index.js:30:38)
     at c.set (/app/node_modules/.pnpm/[email protected][email protected][email protected][email protected][email protected][email protected]/node_modules/next-firebase-auth/build/index.node.js:2:23

Has anyone seen this one before?

[moy2010]

If someone ever faces this issue, it's caused by not setting the COOKIE_SECRET_CURRENT and COOKIE_SECRET_PREVIOUS env variables