Verify canary release

• [X] I verified that the issue exists in the latest Next.js canary release

Provide environment information

Operating System:
      Platform: darwin
      Arch: arm64
      Version: Darwin Kernel Version 22.5.0: Thu Jun  8 22:22:20 PDT 2023; root:xnu-8796.121.3~7/RELEASE_ARM64_T6000
    Binaries:
      Node: 16.18.0
      npm: 8.19.2
      Yarn: 1.22.19
      pnpm: N/A
    Relevant Packages:
      next: 13.4.13-canary.14
      eslint-config-next: 13.4.12
      react: 18.2.0
      react-dom: 18.2.0
      typescript: 5.1.6
    Next.js Config:
      output: standalone

Which area(s) of Next.js are affected? (leave empty if unsure)

Standalone mode (output: "standalone")

Link to the code that reproduces this issue or a replay of the bug

https://github.com/asmockler/next-bug-runtime-env-vars

To Reproduce

Create a standalone app and try to access an environment variable set not-at-build-time.

console.log(process.env.TEST) will evaluate to undefined for both of the following commands:

node .next/standalone/server.js
TEST=present node .next/standalone/server.js

I would expect the first to be undefined and the second to be present

Describe the Bug

Environment variables are not accessible when set after build-time.

Expected Behavior

Environment variables should be accessible and able to be overridden at runtime.

Which browser are you using? (if relevant)

Server-side

How are you deploying your application? (if relevant)

Standalone w/ Docker on Google Cloud Run

I am also having this issue.

In my case, it is making it difficult to initialize some packages (like twilio) because not all of my environment variables are available during the build step. So, these packages throw errors, even though the desired result is just that the code compiles to be run where those environment variables exist.