diff --git a/docs/bugs/rolldown-while-in-globalThis.md b/docs/bugs/rolldown-while-in-globalThis.md
index 419a410..1e9aa6a 100644
--- a/docs/bugs/rolldown-while-in-globalThis.md
+++ b/docs/bugs/rolldown-while-in-globalThis.md
@@ -52,10 +52,16 @@ var dn=`$ark`,fn=2;for(;dn in globalThis;)dn=`$ark${fn++}`;var pn=dn;
 Safari throws: `SyntaxError: Unexpected keyword 'in'. Expected a ';' following a return statement.`
 Chrome and Firefox appear to tolerate the malformed output.
 
+## Reproduction attempts
+
+Direct Rolldown calls (even with the full `arktype` + `@better-fetch/fetch` bundle) do **not** reproduce the bug. It only manifests through Vite's full production build pipeline. This strongly suggests the issue is in the interaction between **Vite's module preprocessing** (dependency pre-bundling, plugin transforms, scope-flattening of ESM modules) and Rolldown's minifier `sequences` optimization pass.
+
+Hypothesis: Vite's pipeline produces a flattened scope where multiple `var` declarations from different original modules are consecutive. When the `sequences` optimizer then tries to fold those `var` declarations into the `for` loop init, it incorrectly drops the `for(var ` prefix when the loop condition contains the `in` operator.
+
 ## Notes
 
-- The bug does **not** reproduce with a minimal isolated input — it is triggered by Rolldown merging multiple module-level `var` declarations across bundled modules before applying the loop optimization.
 - Related closed issue: [rolldown/rolldown#8146](https://github.com/rolldown/rolldown/issues/8146) — "Minifier incorrectly merges statements into for-in expression via comma operator"
+- To reproduce: run `pnpm build` in this project **without** `build.minify: "esbuild"` — the broken chunk is `getAuthor-*.js`
 
 ## Workaround