bun's .env automatic loading feature doesn't work well with Vite's one

[supermacro]

Describe the bug

I am using the build function to programmatically build my vite project.

I have a build.ts file that contains the build({ ... }) function invocation.

I've set the mode to 'production', however my .env.production is not being recognized and vite is incorrectly using the .env.local file.

I made a repro repository which contains two env files:

When I run the build via bun run build.ts (could have also have been via ts-node), and I search for https://myproduction.dev this value is not found. However, when I search for http://localhost:8080, I can see that the value is found.

Reproduction

https://gitlab.com/giioo/vite-build-bug-repro

Steps to reproduce

To reproduce, follow these instructions:

• using either bun or ts-node, run the build.ts file
  • e.g. bun run ./build.ts
• Notice that the built JS file inside of dist/assets/ does not reference the env from .env.production, but rather from .env.local even though the mode has been set to production for the build function inside of build.ts

System Info

System:
    OS: Linux 6.5 Pop!_OS 22.04 LTS
    CPU: (8) x64 Intel(R) Core(TM) i7-10510U CPU @ 1.80GHz
    Memory: 5.93 GB / 15.49 GB
    Container: Yes
    Shell: 5.8.1 - /usr/bin/zsh
  Binaries:
    Node: 18.17.1 - ~/.nvm/versions/node/v18.17.1/bin/node
    npm: 9.6.7 - ~/.nvm/versions/node/v18.17.1/bin/npm
    pnpm: 8.9.0 - ~/.local/share/pnpm/pnpm
    bun: 1.0.7 - ~/.bun/bin/bun
  Browsers:
    Brave Browser: 118.1.59.120
    Chrome: 118.0.5993.88
  npmPackages:
    @vitejs/plugin-react: ^4.0.3 => 4.1.1 
    vite: ^4.4.5 => 4.5.0

Used Package Manager

pnpm

Logs

No response

Validations

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• Read the Contributing Guidelines.
• Read the docs.
• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.
• Make sure this is a Vite issue and not a framework-specific issue. For example, if it's a Vue SFC related bug, it should likely be reported to vuejs/core instead.
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• The provided reproduction is a minimal reproducible example of the bug.

[sapphi-red]

Running node --no-warnings=ExperimentalWarning --loader ts-node/esm build.ts in the root directory works for me. https://myproduction.dev is found in the built file.
I tried with both Windows and WSL.

[supermacro]

Are you able to repro if using bun?

[sapphi-red]

Ah, it did reproduce with bun run.

It's happening because bun loads .env.local and Vite prioritizes environment vars over vars in .env files.
But it seems there's no way to disable the automatic .env load in bun (oven-sh/bun#5515).

I'm not sure what Vite can do here.

[bluwy]

I'd vote closing this one. We don't explicitly support Bun and this doesn't seem like something we should special-case.

[patak-dev]

Let's close this one. I also think it should be handled on Bun's side