Bug Description

When code-splitting, rolldown may place the runtime module (containing __exportAll, __commonJSMin, etc.) inside the entry chunk. If facade elimination later adds __exportAll dependency to a common chunk, that common chunk imports the helper from the entry chunk. When the entry chunk also imports from the common chunk (e.g., through static import chains), a circular dependency is created, causing the helper to be undefined at ESM evaluation time.

Reproduction

Project structure:

entry.js  →  gateway.js  →  daemon.js (barrel: export * from './impl.js')
                              ↑
completion.js  ──── dynamic import('./daemon.js')

Where entry.js also uses a CJS dependency (triggering __commonJSMin runtime helper, placing the runtime in the entry chunk).

Expected: __exportAll is imported from a standalone rolldown-runtime chunk or the chunk that defines it.
Actual: __exportAll is imported from index.js (entry chunk), creating a circular dependency:

daemon-cli-XXXX.js  →  import { __exportAll } from "./index.js"
index.js            →  import { ... } from "./daemon-cli-XXXX.js"

At runtime: TypeError: __exportAll is not a function

Root Cause

In chunk_optimizer.rs, optimize_facade_entry_chunks:

1. The runtime module is assigned to the entry chunk during split_chunks (because only the entry's CJS path references runtime helpers)
2. Facade elimination for dynamic entries adds __exportAll to common chunks
3. The circular dependency check at line ~736 may be bypassed when to_temp_idx() returns None for newly created common chunks
4. The existing code at line ~1005 only handles the case where the runtime is NOT yet assigned (module_to_chunk[runtime_module_idx].is_none()), missing the case where it's already in the entry chunk

Impact

• rc.3 → rc.10 fixed most instances (12 → 1 in our project), but edge cases remain
• The remaining case doesn't crash on startup but causes undefined errors when the affected dynamic import path is executed

Related Issues

• [Bug]: Circular deps caused by advancedChunks would throw error of referenced value is undefined #3650 — Same class of bug (closed, but not fully fixed)
• [Feat]: Inline rolldown:runtime for each chunk instead of share it #2654 — Proposes inlining runtime per-chunk as a more thorough solution