[BUG] Build fails during SSG when custom wrangler.jsonc path is specified

[john-royal]

Describe the bug

If a custom wrangler.jsonc path is used, bindings are inaccessible during opennextjs-cloudflare build even if the correct path is specified in the command.

Steps to reproduce

Please see the reproduction here. The error will be present when running bun run deploy or bun run build. If you use the default path for the wrangler.jsonc, then the error goes away.

More details on reproducing the error from scratch:

1. Initialize a new OpenNext.js/Cloudflare app, add a binding (e.g. KV namespace), and use the binding on a page (e.g. list KV items). This will work as expected during development, build, and deployment.
2. Rename the wrangler.jsonc file and update the relevant parameters (e.g. opennextjs-cloudflare build--configPath custom-wrangler.jsonc, opennextjs-cloudflare deploy--configPath custom-wrangler.jsonc and initOpenNextCloudflareForDev({ configPath: "custom-wrangler.jsonc" });.
3. Development will still work, but the build command will fail, seemingly because the custom wrangler config path is not honored during builds, so the bindings are undefined. The specific error appears during the SSG phase:

   ▲ Next.js 15.4.6

Using vars defined in .dev.vars
Using vars defined in .dev.vars
   Creating an optimized production build ...
Using vars defined in .dev.vars
Using vars defined in .dev.vars
Using vars defined in .dev.vars
 ✓ Compiled successfully in 0ms
 ✓ Linting and checking validity of types    
 ✓ Collecting page data    
Using vars defined in .dev.vars
Error occurred prerendering page "/". Read more: https://nextjs.org/docs/messages/prerender-error
TypeError: Cannot read properties of undefined (reading 'list')
    at j (.next/server/app/page.js:1:3623)
    at async i (.next/server/app/page.js:1:2354) {
  digest: '776967440'
}
Export encountered an error on /page: /, exiting the build.
 ⨯ Next.js build worker exited with code: 1 and signal: null

Expected behavior

SSG should work during opennextjs-cloudflare build when a custom Wrangler --configPath is specified.

@opennextjs/cloudflare version

1.7.0

Wrangler version

4.33.2

next info output

Using vars defined in .dev.vars
/bin/sh: yarn: command not found

Operating System:
  Platform: darwin
  Arch: arm64
  Version: Darwin Kernel Version 24.6.0: Mon Jul 14 11:30:29 PDT 2025; root:xnu-11417.140.69~1/RELEASE_ARM64_T6000
  Available memory (MB): 32768
  Available CPU cores: 10
Binaries:
  Node: 22.15.0
  npm: 10.9.2
  Yarn: N/A
  pnpm: 10.14.0
Relevant Packages:
  next: 15.4.6 // There is a newer version (15.5.2) available, upgrade recommended! 
  eslint-config-next: N/A
  react: 19.1.0
  react-dom: 19.1.0
  typescript: 5.9.2
Next.js Config:
  output: N/A
 ⚠ There is a newer version (15.5.2) available, upgrade recommended! 
   Please try the latest canary version (`npm install next@canary`) to confirm the issue still exists before creating a new issue.
   Read more - https://nextjs.org/docs/messages/opening-an-issue

Additional context

No response