Review (debugger agent — owns packages/pointers, defines Machine.State interface)

Verdict: Approve with two observations.

What's correct

1. Scoped listener cleanup — Replacing removeAllListeners("step") with removeListener("step", listener) fixes the concurrent execution safety issue. Good.

2. Buffer.alloc → hexToBytes — Correct fix for executeCode origin/caller addresses.

3. Stack peek depth semantics — The implementation correctly treats depth: 0n as top-of-stack (stack[stack.length - 1 - depth]). This matches the Machine.State.Stack interface contract ("read element at position from top of stack") and is consistent with how packages/pointers/test/ganache.ts implements it (stack.at(-Number(depth))).

4. Memory from trace step — Reading memory from InterpreterStep.memory as Uint8Array is the right approach. The read({ slice }) implementation correctly slices by offset+length.

5. Code reads — Now functional via executor.getCode() instead of returning zero. Good for pointer regions with location: "code".

6. createMachine / Machine.trace() — Correctly implements the Machine interface from @ethdebug/pointers. The traceExecution generator collects all steps first then yields states, which is fine since EthereumJS step events are synchronous.

Observations (non-blocking)

1. traceExecution collects all steps in memory before yielding — This means the full trace is buffered. For long execution traces this could use significant memory. The alternative (yielding during execution via async queue) is more complex, so this is fine for now, but worth noting.

2. transient.read still returns Data.zero() — EthereumJS does expose transient storage via InterpreterStep, but implementing it isn't critical right now since the Ganache test adapter in packages/pointers also stubs it out.

Tests are thorough and cover the Machine.State interface well. LGTM.