Heap snapshot stuck on 100% with inspect

[ceifa]

What versions & operating system are you using?

Wrangler 4.51.0, Node 22.18, Windows 11, Hono 4.10.7

Please provide a link to a minimal reproduction

Describe the Bug

1. Create a request that takes time
2. In the middle of the request, open the devtools (D) and take a heap snapshot

The heap snapshot never completes, it get stuck on 100%:

If I try to take the snapshot after the request completion, it works, but it's not my use-case.
I initially thought it could be an IO problem, initially I was using SSE and it was in the middle of the writing to the body, but I removed the SSE logic and still didn't work.
I already tried using a debugger, but didn't work either.

Please provide any relevant error logs

After that it returns 503 to all requests and also the current open:
[wrangler:info] POST /history 503 Service Unavailable (68241ms)

[ceifa]

Taking a look at the console of devtools (devtools for devtools) I can see lots of errors like that:

Protocol Error: the message with wrong id: {"id":100000005,"result":{"id":"547d18387ef7910c"}}

It is the same ID pattern miniflare creates to communicate with devtools:

workers-sdk/packages/miniflare/src/plugins/core/inspector-proxy/inspector-proxy.ts

Line 81 in c8e22c3

#runtimeMessageCounter = 1e8;

And looking at the code of heap snapshot on workerd, it looks like it's a problem with busy IO after all: https://github.com/cloudflare/workerd/blob/b6360577505f05c5af00aa75ed7fbc79df721816/src/workerd/io/worker.c%2B%2B#L3131

[Pro2x9]

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