Wrangler crashes and exits on a custom build error issue 10646

[eshentials]

Fixes #10646.

Improve custom build error handling in dev mode to match non-custom build behavior:

1. Initial Build Failures:

   • Exit immediately with error code 1 if the initial build fails
   • Provide clear error messages explaining the build failure

2. Development Build Failures:

   • Continue running the dev server when builds fail during development
   • Return 500 errors for requests when the build is in a failed state
   • Show clear error messages in both console and HTTP responses

3. Error Recovery:

   • Automatically recover when build issues are fixed
   • Clear error state and resume normal operation

4. Testing:

   • Added unit tests for build failure scenarios
   • Added E2E test to verify the complete flow
   • Ensured tests clean up properly

---

• Tests

  • Tests included
    • Unit tests for build failure scenarios
    • E2E test for complete flow verification
  • Tests not necessary because:

• Public documentation

  • Cloudflare docs PR(s):
  • Documentation not necessary because: This is an internal behavior improvement

• Wrangler V3 Backport

  • Wrangler PR:
  • Not necessary because:

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Latest commit: 00a89a1

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[eshentials]

@dario-piotrowicz Hi, pls review.

[eshentials]

@dario-piotrowicz Hi, any update ? @zwily

[dario-piotrowicz]

Hi @eshentials , sorry for the late reply

Your PR contains various changes that seem completely unrelated to #10646, could you double check your changes and make sure that the PR only contains what's related to the issue it's trying to address?

Also the PR description says that an E2E test has been added, but none is