Use a different JavaScript engine

Oct 13, 2025 by pynkocean.com 48 views

Introduction

Rspack is a popular tool for building and serving React applications. However, some users have reported crashes when initializing React with Rspack. In this article, we will delve into the issue, provide a step-by-step guide on how to reproduce the crash, and offer potential solutions to resolve the problem.

Reproducing the Crash

To reproduce the crash, follow these steps:

Step 1: Create a New React Project with Rspack

Create a new React project using Rspack by running the following command:

rspack create my-react-app

This will create a new directory called my-react-app with a basic React project structure.

Step 2: Install Dependencies

Navigate to the project directory and install the required dependencies using the following command:

bun install

This will install the necessary packages, including React, TypeScript, and Biome.

Step 3: Run the Development Server

Start the development server by running the following command:

bun dev

This will start the development server and open the application in your default web browser.

Relevant Log Output

When you run the development server, you may encounter the following log output:

bun dev
$ rsbuild dev --open

  Rsbuild v1.2.18

  ➜ Local:    http://localhost:3000/
  ➜ Network:  http://192.168.1.56:3000/
  ➜ press h + enter to show shortcuts

start   build started...
============================================================
Bun v1.2.4 (fd9a5ea6) macOS Silicon
macOS v15.3.1
Args: "node" "/Users/khanhle/Documents/ai/chatgpt-extension/node_modules/.bin/rsbuild" "dev" "--open"
Features: Bun.stderr(2) Bun.stdin(2) Bun.stdout(2) http_server jsc spawn(2) tsconfig process_dlopen 
Builtins: "bun:jsc" "bun:main" "node:assert" "node:async_hooks" "node:buffer" "node:child_process" "node:constants" "node:crypto" "node:dns" "node:events" "node:fs" "node:fs/promises" "node:http" "node:https" "node:module" "node:net" "node:os" "node:path" "node:perf_hooks" "node:process" "node:querystring" "node:readline" "node:stream" "node:string_decoder" "node:tls" "node:tty" "node:url" "node:util" "node:util/types" "node:vm" "node:zlib" "node:v8" "node:inspector" 
Elapsed: 1047ms | User: 446ms | Sys: 132ms
RSS: 0.27GB | Peak: 0.27GB | Commit: 1.02GB | Faults: 1722

panic(main thread): Segmentation fault at address 0x5
oh no: Bun has crashed. This indicates a bug in Bun, not your code.

To send a redacted crash report to Bun's team,
please file a GitHub issue using the link below:

 https://bun.report/1.2.4/Mn1fd9a5eakIugg0gQ____+qkn3Cu9o76Buql+iCunk6nC+v/0f_A2AK

error: script "dev" was terminated by signal SIGTRAP (Trace or breakpoint trap)
zsh: trace trap  bun dev

Stack Trace (bun.report)

The stack trace from bun.report provides more information about the crash:

Bun v1.2.4 ([`fd9a5ea`](<https://github.com/oven-sh/bun/tree/fd9a5ea668e9ffce5fd5f25a7cfd2d45f0eaa85b>)) on macos aarch64 [RunAsNodeCommand]

Segmentation fault at address 0x00000005

- *4 unknown/js code*
- `llint_call_javascript`
- `JSC::Interpreter::executeCall`
- `JSC::runJSMicrotask`
- `JSC::VM::drainMicrotasks`
- `Bun::jsFunctionDrainMicrotaskQueue`

Features: transpiler_cache, tsconfig, tsconfig_paths, process_dlopen, Bun.stderr, Bun.stdin, Bun.stdout, dotenv, jsc

<!-- from bun.report: 7Rkj6t9Nz0TuYJ73vNJ5 -->

<sub>Sentry Issue: <strong><a href="https://bun-p9.sentry.io/issues/5693081331/">BUN-3XQ</a></strong></sub>

Potential Solutions

Based on the stack trace and log output, it appears that the crash is related to a segmentation fault in the JSC (JavaScriptCore) engine. Here are some potential solutions to resolve the issue:

Update Rspack and Bun: Make sure you are using the latest versions of Rspack and Bun. You can update them by running the following commands:

npm install -g rspack
bun update

Disable JSC caching: Try disabling JSC caching by adding the following flag to your bun.config.js file:

module.exports = {
  // ...
  jsc: {
    cache: false,
  },
};

Use a different JavaScript engine: If you are using a different JavaScript engine, such as V8 or SpiderMonkey, try switching to JSC.
Report the issue: If none of the above solutions work, please report the issue on the Rspack or Bun GitHub repository, providing the relevant log output and stack trace.

Conclusion

Introduction

In our previous article, we explored the issue of crashes when initializing React with Rspack. In this article, we will provide a Q&A guide to help you better understand the problem and its potential solutions.

Q: What is Rspack?

A: Rspack is a popular tool for building and serving React applications. It provides a fast and efficient way to create and deploy React applications.

Q: What is the cause of the crash?

A: The cause of the crash is a segmentation fault in the JSC (JavaScriptCore) engine. This is a complex issue that requires a thorough investigation.

Q: How can I reproduce the crash?

A: To reproduce the crash, follow these steps:

Create a new React project using Rspack by running the following command:

rspack create my-react-app

Install the required dependencies using the following command:

bun install

Start the development server by running the following command:

bun dev

Q: What is the relevant log output?

A: The relevant log output is:

bun dev
$ rsbuild dev --open

  Rsbuild v1.2.18

  ➜ Local:    http://localhost:3000/
  ➜ Network:  http://192.168.1.56:3000/
  ➜ press h + enter to show shortcuts

start   build started...
============================================================
Bun v1.2.4 (fd9a5ea6) macOS Silicon
macOS v15.3.1
Args: "node" "/Users/khanhle/Documents/ai/chatgpt-extension/node_modules/.bin/rsbuild" "dev" "--open"
Features: Bun.stderr(2) Bun.stdin(2) Bun.stdout(2) http_server jsc spawn(2) tsconfig process_dlopen 
Builtins: "bun:jsc" "bun:main" "node:assert" "node:async_hooks" "node:buffer" "node:child_process" "node:constants" "node:crypto" "node:dns" "node:events" "node:fs" "node:fs/promises" "node:http" "node:https" "node:module" "node:net" "node:os" "node:path" "node:perf_hooks" "node:process" "node:querystring" "node:readline" "node:stream" "node:string_decoder" "node:tls" "node:tty" "node:url" "node:util" "node:util/types" "node:vm" "node:zlib" "node:v8" "node:inspector" 
Elapsed: 1047ms | User: 446ms | Sys: 132ms
RSS: 0.27GB | Peak: 0.27GB | Commit: 1.02GB | Faults: 1722

panic(main thread): Segmentation fault at address 0x5
oh no: Bun has crashed. This indicates a bug in Bun, not your code.

To send a redacted crash report to Bun's team,
please file a GitHub issue using the link below:

 https://bun.report/1.2.4/Mn1fd9a5eakIugg0gQ____+qkn3Cu9o76Buql+iCunk6nC+v/0f_A2AK

error: script "dev" was terminated by signal SIGTRAP (Trace or breakpoint trap)
zsh: trace trap  bun dev

Q: What is the stack trace from bun.report?

A: The stack trace from bun.report is:

Bun v1.2.4 ([`fd9a5ea`](<https://github.com/oven-sh/bun/tree/fd9a5ea668e9ffce5fd5f25a7cfd2d45f0eaa85b>)) on macos aarch64 [RunAsNodeCommand]

Segmentation fault at address 0x00000005

- *4 unknown/js code*
- `llint_call_javascript`
- `JSC::Interpreter::executeCall`
- `JSC::runJSMicrotask`
- `JSC::VM::drainMicrotasks`
- `Bun::jsFunctionDrainMicrotaskQueue`

Features: transpiler_cache, tsconfig, tsconfig_paths, process_dlopen, Bun.stderr, Bun.stdin, Bun.stdout, dotenv, jsc

<!-- from bun.report: 7Rkj6t9Nz0TuYJ73vNJ5 -->

<sub>Sentry Issue: <strong><a href="https://bun-p9.sentry.io/issues/5693081331/">BUN-3XQ</a></strong></sub>

Q: What are the potential solutions?

A: The potential solutions are:

Update Rspack and Bun: Make sure you are using the latest versions of Rspack and Bun. You can update them by running the following commands:

npm install -g rspack
bun update

Disable JSC caching: Try disabling JSC caching by adding the following flag to your bun.config.js file:

module.exports = {
  // ...
  jsc: {
    cache: false,
  },
};

Use a different JavaScript engine: If you are using a different JavaScript engine, such as V8 or SpiderMonkey, try switching to JSC.
Report the issue: If none of the above solutions work, please report the issue on the Rspack or Bun GitHub repository, providing the relevant log output and stack trace.

Conclusion

In conclusion, the crash when initializing React with Rspack is a complex issue that requires a thorough investigation. By following the steps outlined in this article, you should be able to reproduce the crash and potentially identify the root cause. If you are still experiencing issues, please report them on the relevant GitHub repository.