[2.0 next, regressed after rc.13] Replacement derived-store rejection never reaches Errored #3887

Describe the bug

A derived store can lose the rejection of a replacement request instead of routing it to the surrounding error boundary.

Your Example Website or App

Standalone reproduction

Steps to Reproduce the Bug or Issue

1. Use the source below with the selected Solid build (complete setup is linked above).

import { createSignal, createStore, Errored, Loading } from "solid-js";
export default function App() {
  let reject!: (error: Error) => void;
  const replacement = new Promise<{ value: number }>((_, fail) => {
    reject = fail;
  });
  const [id, setId] = createSignal(0);
  const [store] = createStore(() => (id() ? replacement : { value: 0 }), { value: 0 });
  function replace() {
    setId(1); // Start a replacement request.
    setTimeout(() => reject(new Error("replacement failed")), 20);
  }
  return (
    <>
      <button id="trigger" onClick={replace}>
        Replace and reject
      </button>
      <Errored fallback={() => <b id="answer">error</b>}>
        <Loading fallback={<i>pending</i>}>
          <span id="answer">{store.value}</span>
        </Loading>
      </Errored>
    </>
  ); // After the click: still 0, instead of the error fallback.
}

2. Paste this App into a Solid 2 playground. Click Replace and reject, then wait.

Expected behavior

Expected: The error fallback displays error.
Actual: The previous value 0 remains visible.

Platform

• Solid: solid-js / @solidjs/web next at 3086f1b77cd7b0431d3a7f768c2984c335758633; comparison 2.0.0-rc.13. Signals, compiler and diagnostics match the selected Solid build.
• OS: macOS 26.6.2 (25G83); browser cases: system Google Chrome 155.0.8059.40. Server-only/type checks run in Bun 1.4.2.
• Builds/comparison: development and production fail. rc.13 passes in both builds.

Additional context

The surrounding Errored boundary should handle rejection of the data it displays; keeping the old successful value hides the failed request.

Related: #2997, #3769

bun init -y
bun add solid-js@2.0.0-rc.13 @solidjs/web@2.0.0-rc.13 @solidjs/signals@2.0.0-rc.13 @solidjs/compiler@2.0.0-rc.13 @solidjs/diagnostics@2.0.0-rc.13
bun add -d playwright
bun run link-head.ts /absolute/path/to/built/solid
BUILD_MODE=development bun test ./snippet.test.ts