Solid.js 'multiple instances' warnings appear in React apps with Vite 8

[abed-daloopa]

TanStack Devtools version

@tanstack/react-devtools v0.10.1, @tanstack/devtools-vite v0.6.0

Framework/Library version

React 19.2.4, TanStack Start 1.167.16, Vite 8.0.3

Describe the bug and the steps to reproduce it

When using TanStack Devtools in a React TanStack Start app with Vite 8, the following warnings appear in the terminal and browser when starting the dev server

❯ bun run dev
$ vite dev --port 3000

  VITE v8.0.3  ready in 1039 ms

  ➜  Local:   http://localhost:3000/
  ➜  Network: use --host to expose
  ➜  press h + enter to show help
[vite] connected.
9:48:32 AM [vite] (client) [console.warn] You appear to have multiple instances of Solid. This can lead to unexpected behavior.
9:48:32 AM [vite] (client) [console.warn] You appear to have multiple instances of Solid. This can lead to unexpected behavior.
9:48:32 AM [vite] (client) [console.warn] computations created outside a `createRoot` or `render` will never be disposed
9:48:32 AM [vite] (client) [console.warn] computations created outside a `createRoot` or `render` will never be disposed
9:48:32 AM [vite] (client) [console.warn] cleanups created outside a `createRoot` or `render` will never be run
9:48:32 AM [vite] (client) [console.warn] computations created outside a `createRoot` or `render` will never be disposed
9:48:32 AM [vite] (client) [console.warn] computations created outside a `createRoot` or `render` will never be disposed
9:48:32 AM [vite] (client) [console.warn] cleanups created outside a `createRoot` or `render` will never be run
9:48:32 AM [vite] (client) [console.warn] computations created outside a `createRoot` or `render` will never be disposed
9:48:32 AM [vite] (client) [console.warn] cleanups created outside a `createRoot` or `render` will never be run
9:48:32 AM [vite] (client) [console.warn] cleanups created outside a `createRoot` or `render` will never be run
9:48:32 AM [vite] (client) [console.warn] computations created outside a `createRoot` or `render` will never be disposed

These warnings do not appear with Vite 7 using the exact same dependencies and configuration.

Steps to reproduce:

1. Clone the repro repo and install dependencies:

   git clone https://github.com/abed-daloopa/tanstack-devtools-solid-warnings
   cd tanstack-devtools-solid-warnings
   bun install

2. Run the dev server:

   bun run dev

3. Open http://localhost:3000 — warnings appear in the browser console and terminal.

To verify Vite 8 is the cause, downgrade to Vite 7:

- "vite": "^8.0.3"
+ "vite": "^7.3.1"

Or add resolve.dedupe: ["solid-js"] to vite config

Reinstall and run ➡︎ warnings disappear.

Root cause: Vite 8 resolves Solid.js as multiple instances at runtime, even when only one copy exists in node_modules. Vite correctly deduplicates it.

Note: Adding resolve.dedupe: ["solid-js"] to the Vite config fixes the issue.

Your Minimal, Reproducible Example - (Sandbox Highly Recommended)

https://github.com/abed-daloopa/tanstack-devtools-solid-warnings

Screenshots or Videos (Optional)

No response

Do you intend to try to help solve this bug with your own PR?

Maybe

Terms & Code of Conduct

• I agree to follow this project's Code of Conduct
• I understand that if my bug cannot be reliable reproduced in a debuggable environment, it will probably not be fixed and this issue may even be closed.

[rbrito02]

@tanstack/devtools-vite already has a config() hook at src/plugin.ts (@tanstack/devtools:config) that currently does nothing during serve mode (just returns). A minimal fix would be to return resolve.dedupe from it so Vite 8 collapses all solid-js imports into a single instance:

  {
    name: "@tanstack/devtools:config",
    enforce: "pre",
    config(_, { command }) {
      if (command !== "serve") {
        return;
      }
      return {
        resolve: {
          dedupe: ["solid-js"],
        },
      };
    },
  },

If looks good will make PR for it

[rbrito02]

have been having some issue today though after updating deps on project

[abed-daloopa]

Another issue with Vite 8 (not sure what the cause exactly)

I have to add devtools({ consolePiping: { enabled: false } }) to the vite config or I will get spammed by an infinte number of messages whenever an error happens

[rbrito02]

I've had this spam reported if serving bun run dev from a terminal within ide (e.g. cursor, vscode). But doesn't seem to occur in terminal apps (e.g. terminal, iterm2, ghostty). However, error spam is strong enough to freeze dev environment.

[rbrito02]

Seems to be caused by the following flow:

1. Vite 8 loading in 2 Solid.Js instances
2. Solid code execution fires multiple instances warning
3. consolePiping grabs it and POSTS to /_tsd/console-pipe
4. devtool server receives it and sends to panel
5. panel is built with Solid causing another code execution (loop restarts)

could use a guard to prevent repeated calls.

@abed-daloopa when enabling dedupe for solidJS did you still have the infinite errors?

[abed-daloopa]

when enabling dedupe for solidJS did you still have the infinite errors?

This issue is unrelated to the Solid.Js multiple instances problem.

Even when adding dedupe: ["solid-js"]

If any other error happens, I get spammed if i don't set { consolePiping: { enabled: false } }

Note: I am running bun run dev inside Cursor's integrated terminal