next.config.js executes multiple times?

[paul-vd]

Hi,

So with my current setup, I noticed that the in dev mode next dev the next.config.js export runs twice.

The isDev, isProd, isStaging console log happens within the building phase and I would expect it to run once.

I never experienced this with the previous versions.

Here is the example of my current next.config.js: https://github.com/PaulPCIO/nextjs-boilerplate-ts/blob/master/next.config.js

[williamhaley]

I noticed this today as well with [email protected] for a dev build. I see next.config.js evaluated two times.

Towards the top of next.config.js I have a console.log(process.argv). See how the two examples here differ.

First iteration

[
  '/Users/will.haley/.nodenv/versions/18.18.2/bin/node',
  '/Users/will.haley/src/my_app_redacted/node_modules/.bin/next',
  'dev',
  '-p',
  '8082'
]

Second iteration

[
  '/Users/will.haley/.nodenv/versions/18.18.2/bin/node',
  '/Users/will.haley/src/my_app_redacted/node_modules/next/dist/server/lib/start-server.js'
]

Not sure why, but I'm assuming loadConfig gets invoked multiple times between these two iterations. https://github.com/vercel/next.js/blob/v14.0.3/packages/next/src/server/config.ts#L888C31-L888C41

[canmeng568]

how to solve?

[rcronin]

I'm not proud of this and not sure if this use case will work for everyone. I suppose it depends on what you're trying to do. I have a high order function being invoked in our next config to do some additional pre-compilations that needs to be run only once before the app builds/starts. I am checking for process.argv[1].includes('.bin/next'). I only run my pre-compilation if that is true.

Definitely not a fix...but a workaround.