mongodb 7.6.0: insertOne after deleteMany rejects with "reading 'state'" and the process hangs

[proggeramlug]

Found by the Phase 1 package benchmark harness (benchmarks/packages/mongodb/insert_find.ts, branch wip/pkg-bench-phase1). Reproduces on main 36420d2e56 (Linux x86-64, mongod 8.x, mongodb 7.6.0 compiled from source).

Sequential insertOne + findOne round trips work for hundreds of iterations, but after a deleteMany({}) on the same collection, the next insertOne rejects with Cannot read properties of undefined (reading 'state'), and the process then hangs (never exits) instead of finishing. The workload's shape (the numbers below are from the workload binary itself, not from this condensed snippet):

// npm i mongodb@7.6.0 ; mongod on 127.0.0.1:57017
import { MongoClient } from "mongodb";
const client = new MongoClient("mongodb://127.0.0.1:57017/?directConnection=true");
await client.connect();
const col = client.db("pkgbench").collection("items_if");
await col.deleteMany({});
const once = async (i: number) => {
  await col.insertOne({ _id: "d" + i, n: i } as any);
  return (await col.findOne({ _id: "d" + i } as any)) as any;
};
for (let i = 0; i < 200; i++) await once(i);   // "warm-up"
await col.deleteMany({});
for (let i = 0; i < 500; i++) await once(i);   // perry: rejects here
await col.drop(); await client.close();
console.log("done");

Measured with the workload binary (./mongodb__insert_find <n> <warm>):

args	perry (main)	node 26.5.1
500 0 (no warm-up, so no mid-run deleteMany)	correct checksum, 12 s	same checksum
500 200	ERROR Cannot read properties of undefined (reading 'state'), then no exit (killed at 120 s)	correct
2000 200	no output, killed at 120 s	correct

The companion workload mongodb/batch_query (insertMany + find().sort().project().toArray() + countDocuments, also with a mid-run deleteMany) runs correctly on the same server. Distinct from #11043 (reading 'default' on connect). The harness now skips this workload as a known hang (manifest known_hang).

[proggeramlug]

The package matrix re-run (#11723) at 9e29f59 found that mongodb/insert_find now runs correctly and no longer hangs. It is 222× Node on instructions and peaks at 1,185 MB vs Node's 115 MB. Can this issue be closed as fixed? The perf gap is tracked separately.