bug: `vite:anonymous:auth` fails on StackBlitz: `DF0020` masks `DTK0011` (Error in `jsonSerializable: true` response)

[baseballyama]

Describe the bug

Summary

On StackBlitz (WebContainer / Node 22), the initial vite:anonymous:auth call throws and the dev server crashes. DevTools never connects.

The handler in vite:anonymous:auth is declared jsonSerializable: true. When it throws, birpc wraps the rejection into { id, e: <Error> } and the WS transport runs strictJsonStringify on the whole envelope, which then fails with DF0020 because e is an Error. The original DTK0011 is lost and the process exits.

Environment

- StackBlitz WebContainer, Node `v22.22.0`, Vite `8.0.12`
- `@vitejs/devtools@0.1.21`, `devframe@0.1.21/0.1.22`, `birpc@4.0.0`

Log

> playground@0.0.1 dev /home/projects/pariqzvbqw.github/playground
> vite dev

(node:131) ExperimentalWarning: WASI is an experimental feature and might change at any time
(Use `node --trace-warnings ...` to show where the warning was created)
(node:131) ExperimentalWarning: WASI is an experimental feature and might change at any time
(Use `node --trace-warnings ...` to show where the warning was created)
(node:131) ExperimentalWarning: WASI is an experimental feature and might change at any time
(Use `node --trace-warnings ...` to show where the warning was created)

  VITE v8.0.12  ready in 2653 ms

  ➜  Local:   http://localhost:5173/
  ➜  Network: use --host to expose
  ➜  press h + enter to show help
ℹ Websocket client connected. [0] [undefined] (untrusted)
[DTK0011] RPC error on executing "vite:anonymous:auth"
╰▶ see: https://devtools.vite.dev/errors/dtk0011
[DF0020] RPC function "vite:anonymous:auth" declares `jsonSerializable: true` but the value at "e" is a Error.
├▶ hint: Either drop `jsonSerializable: true` (falls back to structured-clone) or change the value to a JSON-safe shape.
╰▶ see: https://devfra.me/errors/df0020
[DTK0012] RPC error on executing rpc
╰▶ see: https://devtools.vite.dev/errors/dtk0012
CodedError: [DF0020] RPC function "vite:anonymous:auth" declares `jsonSerializable: true` but the value at "e" is a Error.
    at new CodedError (file:///home/projects/pariqzvbqw.github/node_modules/.pnpm/logs-sdk@0.0.6/node_modules/logs-sdk/dist/index.mjs:92:3)
    at Object.throw (file:///home/projects/pariqzvbqw.github/node_modules/.pnpm/logs-sdk@0.0.6/node_modules/logs-sdk/dist/index.mjs:141:10)
    at nonJsonAt (file:///home/projects/pariqzvbqw.github/node_modules/.pnpm/devframe@0.1.22_typescript@6.0.3/node_modules/devframe/dist/serialization-CwO31axa.mjs:121:10)
    at Object.strictReplacer (file:///home/projects/pariqzvbqw.github/node_modules/.pnpm/devframe@0.1.22_typescript@6.0.3/node_modules/devframe/dist/serialization-CwO31axa.mjs:110:60)
    at Module.strictJsonStringify (file:///home/projects/pariqzvbqw.github/node_modules/.pnpm/devframe@0.1.22_typescript@6.0.3/node_modules/devframe/dist/serialization-CwO31axa.mjs:95:14)
    at eval (file:///home/projects/pariqzvbqw.github/node_modules/.pnpm/devframe@0.1.22_typescript@6.0.3/node_modules/devframe/dist/rpc/transports/ws-server.mjs:64:108)
    at onMessage (file:///home/projects/pariqzvbqw.github/node_modules/.pnpm/birpc@4.0.0/node_modules/birpc/dist/index.mjs:207:17) {
  diagnostic: {
    code: 'DF0020',
    level: 'error',
    message: 'RPC function "vite:anonymous:auth" declares `jsonSerializable: true` but the value at "e" is a Error.',
    docs: 'https://devfra.me/errors/df0020',
    hint: 'Either drop `jsonSerializable: true` (falls back to structured-clone) or change the value to a JSON-safe shape.'
  }
}

Node.js v22.22.0
 ELIFECYCLE  Command failed with exit code 1.
 ELIFECYCLE  Command failed with exit code 1.

Suggested fix (by Claude Code)

jsonSerializable: true is a contract about the result, not about thrown errors. The error slot (e) should not be passed through strictJsonStringify; coerce it to { name, message, stack } or use structured-clone serialization regardless of the flag.

This also makes the underlying handler failure (DTK0011) visible instead of masked by DF0020.

Reproduction

https://stackblitz.com/github/baseballyama/vite-devtools-svelte

System Info

System:
    OS: macOS 26.3
    CPU: (12) arm64 Apple M4 Pro
    Memory: 111.70 MB / 48.00 GB
    Shell: 5.9 - /bin/zsh
  Binaries:
    Node: 24.13.0 - /Users/baseballyama/.nodenv/versions/24.13.0/bin/node
    npm: 11.12.1 - /Users/baseballyama/.nodenv/versions/24.13.0/bin/npm
    pnpm: 10.25.0 - /Users/baseballyama/.nodenv/versions/24.13.0/bin/pnpm
    bun: 1.3.11 - /opt/homebrew/bin/bun
    Deno: 2.5.6 - /opt/homebrew/bin/deno

Used Package Manager

pnpm

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