Hi all!
I'm deploying Next.js app in standalone mode in AWS ECS Fargate - basically I build a Docker image and AWS takes care of it.
It worked perfectly well until a few days ago when I upgraded from Next 13.4.7 to 13.4.18 and my app started crashing. Soon it was clear all my environment variables are not there.
After some investigation I found out that all versions through 13.4.12 work fine, but 13.4.13 and above don't.
In the release notes for 13.4.13 I didn't notice anything suspicious, but I'm not that experienced in the Next.js community to know what to look for.

I use [the Dockerfile](https://github.com/vercel/next.js/blob/canary/examples/with-docker/Dockerfile) that is linked in [the Next.js docs](https://nextjs.org/docs/pages/building-your-application/deploying#docker-image).

My next.config.js:

/** @type {import('next').NextConfig} */
const nextConfig = {
  reactStrictMode: true,
  swcMinify: true,
  images: {
    remotePatterns: [
      {
        protocol: 'https',
        hostname: '**'
      }
    ]
  },
  output: 'standalone',
}
module.exports = nextConfig

As you can see I don't declare the environment variables there. I'm directly accessing them in the code with process.env.VAR_NAME.

When I run a container from the image locally and pass an environment variable to it with -e VAR_NAME=value it works fine with Next.js 13.4.12 but not with 13.4.13 and above.

docker run -it -p 3000:3000 -e VAR_NAME=value my-image:latest

I would appreciate any help or advice on how to debug this issue. I'd like to use latest Next.js in the end.

Here is next info if it helps:

Operating System:
  Platform: linux
  Arch: x64
  Version: #1 SMP PREEMPT_DYNAMIC Thu May 11 16:51:53 UTC 2023
Binaries:
  Node: 18.12.1
  npm: 8.1.3
  Yarn: 1.22.17
  pnpm: 8.6.12
Relevant Packages:
  next: 13.4.13
  eslint-config-next: 13.4.18
  react: 18.2.0
  react-dom: 18.2.0
  typescript: 5.1.6
Next.js Config:
  output: standalone