[IGN-Styly]

Why mods crash today

enginelib turns on rust-rocksdb's jemalloc feature, and librocksdb-sys builds tikv-jemalloc-sys with unprefixed_malloc_on_supported_platforms, so jemalloc replaces malloc/free. Mods are cdylibs that link enginelib statically, so every mod carried its own private jemalloc:

• release mods could fail dlopen with "cannot allocate memory in static TLS block" (jemalloc uses initial-exec TLS), or
• memory allocated on one heap and freed on the other while crossing run(&mut ServerAPI) (Arc<dyn Task>, Strings, registry entries) corrupts the heap.

Fix

Enable the feature in engine/Cargo.toml (host binaries) instead. The server still runs entirely on jemalloc (it exports malloc/free; checked with nm -D), and a mod built on its own has no allocator of its own: its malloc binds to the host's at load time, so there is one heap per process. Mods must be built as separate projects (the voltaero/mod template / cargo rf), not in a --workspace build with the engine, where the feature would unify back in. Documented in AGENTS.md.

Also carried from the magnesium work (ccc4318, already pinned by voltaero/magnesium):

• #[derive(Verifiable)] matches verify(&self, &[u8]).
• Client::connect_timeout bounds the Hello handshake.
• EventBus::fire no longer records events (auth challenges / admin tokens) in its tracing span.

cargo test --workspace passes.

🤖 Generated with Claude Code

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Reviewing files that changed from the base of the PR and between 25716a1 and 7228a7f.

Files ignored due to path filters: 1

• Cargo.lock is excluded by !**/*.lock

Files selected for processing: 8

• AGENTS.md
• engine/Cargo.toml
• enginelib/Cargo.toml
• enginelib/macros/src/lib.rs
• enginelib/src/event.rs
• enginelib/src/transport/client.rs
• enginelib/tests/macros.rs
• enginelib/tests/transport.rs

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[greptile-apps]

Confidence Score: 5/5

[Medium impact] The PR appears safe to merge; both previous findings are addressed and no new actionable issues were found.

Summary

Moves RocksDB's jemalloc feature from enginelib to the host binaries and documents how to build mods separately.

• The engine host owns jemalloc while separately built mods stay allocator-neutral.
• Clients can choose how long the handshake waits.
• Derived verifiers check payloads from a borrowed byte slice.
• Event spans leave event contents out of tracing.
• Repository housekeeping leaves engine behavior unchanged.

Both previous test-coverage findings are addressed. No new actionable issues were found in the changes since the previous review.

Diagram

%%{init: {'theme': 'neutral'}}%%
flowchart LR
  Host["engine host binaries"] -->|"enables jemalloc"| RocksDB["rust-rocksdb"]
  Host --> Library["enginelib"]
  Mod["Separately built mod"] --> Library
  Library -->|"does not enable jemalloc"| RocksDB

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_{Reviews (2) · Last reviewed commit: "test: cover #[derive(Verifiable)] and Cl..." · Reviewed by Greptile}