`process.env` overwritten with `{ SVELTEKIT_FORK: true }` on Netlify

[james-camilleri]

Describe the bug

Ever since version 1.3.1 the entirety of process.env is being overwritten with an object containing a single key, { SVELTEKIT_FORK: true }. Using SvelteKit's $env/static/private handling works, but process.env is still totally overwritten. I'm not sure if this is by design.

Reproduction

https://stackblitz.com/edit/sveltejs-kit-template-default-u765us?file=package.json

This repo does not show the entire process.env being overwritten, probably due to the different functioning of WebContainers to Netlify's environment. You can still notice env variables being overwritten by changing between versions 1.3.0 and 1.3.1.

v1.3.0:

process.env {
  COLORTERM: 'truecolor',
  TERM: 'xterm-256color',
  LSCOLORS: 'ExGxBxDxCxEgEdxbxgExEx',
  PATH: '/home/projects/sveltejs-kit-template-default-u765us/node_modules/.bin:/home/projects/node_modules/.bin:/home/node_modules/.bin:/node_modules/.bin:/bin:/usr/bin:/usr/local/bin',
  HOME: '/home',
  SHELL: '/bin/jsh',
  HISTFILE: '/home/.jsh_history',
  TMPDIR: '/tmp',
  CHROME_BIN: '/usr/local/bin/google-chrome',
  GIT_PROXY: 'https://p.stackblitz.com',
  PWD: '/home/projects/sveltejs-kit-template-default-u765us',
  NEXT_TELEMETRY_DISABLED: '1',
  ASTRO_TELEMETRY_DISABLED: '1',
  __NEXT_DISABLE_MEMORY_WATCHER: '1',
  NG_CLI_ANALYTICS: 'false',
  EDITOR: 'code',
  PKG_MANAGER: 'npm',
  NODE_ENV: 'production'
}

v1.3.1

process.env {
  COLORTERM: 'truecolor',
  TERM: 'xterm-256color',
  LSCOLORS: 'ExGxBxDxCxEgEdxbxgExEx',
  PATH: '/bin:/usr/bin:/usr/local/bin',
  HOME: '/home',
  SHELL: '/bin/jsh',
  HISTFILE: '/home/.jsh_history',
  TMPDIR: '/tmp',
  CHROME_BIN: '/usr/local/bin/google-chrome',
  GIT_PROXY: 'https://p.stackblitz.com',
  PWD: '/home/projects/sveltejs-kit-template-default-u765us',
  SVELTEKIT_FORK: 'true'
}

Logs

12:21:09 AM:   Netlify Build                                                 
12:21:09 AM: ────────────────────────────────────────────────────────────────
12:21:09 AM: ​
12:21:09 AM: ❯ Version
12:21:09 AM:   @netlify/build 29.5.1
12:21:09 AM: ​
12:21:09 AM: ❯ Flags
12:21:09 AM:   baseRelDir: true
12:21:09 AM:   buildId: 63d5bbde011c720008ba785d
12:21:09 AM:   deployId: 63d5bbde011c720008ba785f
12:21:09 AM: ​
12:21:09 AM: ❯ Current directory
12:21:09 AM:   /opt/build/repo/sites/web
12:21:09 AM: ​
12:21:09 AM: ❯ Config file
12:21:09 AM:   /opt/build/repo/sites/web/netlify.toml
12:21:09 AM: ​
12:21:09 AM: ❯ Context
12:21:09 AM:   production
12:21:09 AM: ​
12:21:09 AM: ❯ Loading plugins
12:21:09 AM:    - @netlify/plugin-lighthouse@4.0.7 from Netlify app
12:21:11 AM: ​
12:21:11 AM:   1. build.command from netlify.toml                            
12:21:11 AM: ────────────────────────────────────────────────────────────────
12:21:11 AM: ​
12:21:11 AM: $ npm run build
12:21:11 AM: > tickets@0.0.1 build
12:21:11 AM: > vite build
12:21:11 AM: ▲ [WARNING] Cannot find base config file "./.svelte-kit/tsconfig.json" [tsconfig.json]
12:21:11 AM:     tsconfig.json:2:13:
12:21:11 AM:       2 │   "extends": "./.svelte-kit/tsconfig.json",
12:21:11 AM:         ╵              ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
12:21:12 AM: vite v4.0.4 building SSR bundle for production...
12:21:12 AM: transforming...
12:21:14 AM: ../assets/fonts/font.woff2 referenced in /opt/build/repo/sites/web/src/styles/global.scss didn't resolve at build time, it will remain unchanged to be resolved at runtime
✓ 115 modules transformed.
12:21:14 AM: 12:21:14 AM [vite-plugin-svelte] ssr compile done.
12:21:14 AM: package             	files	  time	   avg
12:21:14 AM: tickets             	   11	 0.32s	28.7ms
12:21:14 AM: @portabletext/svelte	   15	51.6ms	 3.4ms
12:21:14 AM: @sveltejs/kit       	    2	21.4ms	10.7ms
12:21:14 AM: Generated an empty chunk: "entries/endpoints/api/booking/_server.ts".
12:21:14 AM: rendering chunks...

... CHUNKS BEING RENDERED HERE

12:21:15 AM: .svelte-kit/output/client/_app/immutable/components/pages/(public)/_page.svelte-9b90a5a9.js    84.67 kB │ gzip: 13.23 kB
12:21:16 AM: { SVELTEKIT_FORK: 'true' } <-- This is just me writing `console.log(process.env)` in a file imported by a +server.ts file

System Info

This was observed on a standard Netlify deployment with adapter-auto, however the only changes in the package-lock file between a system with a successful build and one with a failed one are with '@sveltejs/kit': 1.3.1, so I would assume the issue is not in the Netlify or auto adapters.

Severity

annoyance

Additional Information

No response

[gtm-nayan]

In #8636, Kit started running prerendering and postbuild analysis in child processes, which inherit environment variables set by the OS, but for others, eg. loaded through dotenv, they have to be passed in manually here.

[csellis]

I have been trying to track down this all weekend, we started having build failures on Jan 25th

[james-camilleri]

Oh I see @gtm-nayan. I'm not sure how Netlify is loading the env variables in question under the hood - they're set through the Netlify web interface and they're usually where they're expected to be when the build runs. I'm still not sure whether this is an oversight or a necessary part of the change - if it's the latter it might make sense to document that process.env is ignored and you should stick to using SvelteKit's $env modules.

[james-camilleri]

Can confirm that the new version solves the problem, thanks!