Symlinked .env Parsing Failing During next build: "Module parse failed: Unexpected token"

[gchallen]

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: 16.20.1
      npm: 9.8.0
      Yarn: N/A
      pnpm: N/A
    Relevant Packages:
      next: 13.4.12-canary.0
      eslint-config-next: 13.4.12
      react: 18.2.0
      react-dom: 18.2.0
      typescript: 5.1.3
    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/gchallen/environment-variable-parsing-problem

To Reproduce

Run next build in a project with a symlinked .env file (and that has certain tokens).

Describe the Bug

.env file parsing seems to have changed in a recent version of NextJS, which is breaking our builds which worked previously. Here's an example error output:

Found configuration in /Users/challen/www/cs124.org/rush.json

- info Loaded env from /Users/challen/www/cs124.org/sites/cs124/.env.local                                                                   [37/1958]
- info Loaded env from /Users/challen/www/cs124.org/sites/cs124/.env.production
- warn You have enabled experimental feature (outputFileTracingRoot) in next.config.js.
- warn Experimental features are not covered by semver, and may cause unexpected or broken application behavior. Use at your own risk.

- info Linting and checking validity of types
Failed to compile.

../../.env.development
Module parse failed: Unexpected token (7:17)
You may need an appropriate loader to handle this file type, currently no loaders are configured to process this file. See https://webpack.js.org/conc
epts#loaders
| SEMESTER=Summer2023
|
> NEXTAUTH_URL=http://localhost:1124
...

There are similar errors in .env.production.

I figured that I could work around this by adding some quoting in places that either NextJS or webpack wanted it. But this problem is also preventing the use of commented-out settings, since it doesn't seem to accept (and ignore) lines started with #. This is a bit of a more serious problem, since given that some of our .env files are not checked into version control, it's important from a sanity perspective to restore the names of disabled settings so they can be enabled and disabled without forgetting what they are called.

This seems to have cropped up in NextJS 13.4.11, or at least 13.4.10 is the latest working version.

Perhaps there is a way to exclude these files from the build once their values have been loaded by NextJS, so that webpack doesn't trip over them? .env.development in particular isn't even being used in the build process.

After a bit more poking around, this seems to only be triggered when the .env file is symlinked into the NextJS build directory. Please see the reproduction repository for an example. Note that it has an extra level of directories to allow the symlink into the root.

Expected Behavior

NextJS should build the project correctly.

Which browser are you using? (if relevant)

Chrome

How are you deploying your application? (if relevant)

Other platform (local infrastructure via Docker container)

[ykzts]

This problem seems to occur not only in Standalone mode, but also when using the app router.

[gchallen]

Yes, sorry. I chose standalone because there didn't seem to be a way to leave that blank in the form used to create the initial issue. (Or maybe I missed it.)

[hanoii]

This is happening for me as well!

[hanoii]

As a workaround, I added /* to the first line on its own and */ to the end and it worked! I thought it wasn't going to, but it did!

/*
# This is some symlinked .env file
ENV1=Hello
ENV2=World
*/

So you can keep all of your comments

[gchallen]

This is a hilarious workaround. Thanks! It works, but please can we fix this in NextJS :-).

[gchallen]

Actually, I spoke to soon. This seems to work for next, but breaks other tools that read .env files, like env-cmd.

[hanoii]

It was bound to happen, it's not very .env compliant, but as seeing next not complaining gave me hope

[hanoii]

@gchallen

Actually, I spoke to soon. This seems to work for next, but breaks other tools that read .env files, like env-cmd.

Out of curiosity I tried env-cmd and it seems to work.

[gchallen]

Hmmm... Maybe it was Docker compose that blew up then? Something crashed when I tried your fix.

[ShubhamPalriwala]

I'm able to reproduce the bug in NextJs App directory project for versions > 13.4.12!

@hanoii's workaround helps but I think we would still need a cleaner fix in the core!

[neongreen]

Still an issue on 13.5.2.

[9vfQbg7z4ajrGQxR]

Issue on 13.5.2, temporary fix is it to remove symlink (and use a copy of file during build step) but this is not a viable solution. Edit: Problem happened at 13.4.11

[gempi]

If you use tubrorepo you can follow this guide as a workaround. This helped me to get rid of the .env symlinks in my monorepo.

[marreman]

My .dockerignore is symlinked to .gitignore. I'm getting this error as well.

[panta82]

Inspired by @hanoii , this works for me.

X=0/*

# The rest of env

#*/