runtime.setMemoryLimit doesn’t prevent host OOM with prebuilt wasm (memory growth enabled)

[fedorkar]

Repro

import ReleaseSync from "@jitl/quickjs-wasmfile-release-sync";
import { newQuickJSWASMModuleFromVariant } from "quickjs-emscripten-core";

const QuickJS = await newQuickJSWASMModuleFromVariant(ReleaseSync);
const rt = QuickJS.newRuntime();
rt.setMemoryLimit(64 * 1024 * 1024);

const ctx = rt.newContext();
ctx.evalCode(`
  const chunks = [];
  while (true) { chunks.push("x".repeat(1024 * 1024)); }
`);

Expected

QuickJS throws an OOM error when the limit is exceeded.

Actual

Process memory keeps growing and the host eventually OOMs / runtime crashes. No QuickJS OOM is raised.

Note / workaround

If I build a custom wasm with:

• MPORTED_MEMORY=1
• ALLOW_MEMORY_GROWTH=0
• fixed INITIAL_MEMORY/MAXIMUM_MEMORY
  and pass a fixed WebAssembly.Memory via newVariant, the same script consistently throws a QuickJS OOM instead of crashing.

Question

Is there a prebuilt “fixed memory” variant intended for sandbox use, or a recommended way to enforce hard memory caps with the prebuilt wasm?