Segmentation fault when using FileSystemRouter as callable function

[userCasWeb]

How can we reproduce the crash?

Make a dir with name 'frontend' and paste some html, css and js files in it. In the cwd make a file 'fileSystemRouter.js'. Then run the 'fileSystemRouter.js' in watch mode.

bun --watch 'fileSystemRouter.js'

// -> fileSystemRouter.js

const router = () => new Bun.FileSystemRouter({
  style: "nextjs",
  dir: process.cwd() + "/frontend",
  assetPrefix: "/",
  fileExtensions: ['.html', '.css', '.js'],
});

console.log(
  router().routes,
  Object.keys(router().routes),
);

const server = Bun.serve({
  port: 8000,
  hostname: '127.0.0.1',
  development: false,
  fetch: async req => {
    const url = new URL(req.url);
    const match = router().match(url.pathname)
    return match
      ? new Response(Bun.file(match.filePath))
      : new Response("404!", { status: '404' });
  }
});

Without console.log it works. No crash. The same goes with commenting one of the log statements or the assetPrefix in the router.

console.log(
  // router().routes,
  Object.keys(router().routes),
);

OR:

console.log(
  router().routes,
  // Object.keys(router().routes),
);

OR:

const router = () => new Bun.FileSystemRouter({
  style: "nextjs",
  dir: process.cwd() + "/frontend",
  // assetPrefix: "/",
  fileExtensions: ['.html', '.css', '.js'],
});

Relevant log output

Bun v1.1.26 (0a37423b) macOS Silicon
macOS v14.6.1
Args: "bun" "--watch" "fileSystemRouter.js"
Features: jsc http_server tsconfig(3) 
Builtins: "bun:main" "node:path" 
Elapsed: 9ms | User: 1242ms | Sys: 2472ms
RSS: 38.70MB | Peak: 38.70MB | Commit: 1.07GB | Faults: 9077

panic(main thread): Segmentation fault at address 0x0

Stack Trace (bun.report)

Bun v1.1.26 (0a37423) on macos aarch64 [AutoCommand]

Segmentation fault at address 0x00000000

• 2 unknown/js code
• WTF::StringImpl::destroy
• FileSystemRouterClass__finalize
• JSC::PreciseAllocation::sweep
• JSC::MarkedSpace::sweepPreciseAllocations
• JSC::Heap::finalize
• JSC::Heap::handleNeedFinalize
• JSC::Heap::finishChangingPhase
• JSC::Heap::runEndPhase