fix(mcp): drain elicitation_rx concurrently in run_inline_tool_loop#2548
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fix(mcp): drain elicitation_rx concurrently in run_inline_tool_loop#2548
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…2542) Phase 3 fix for elicitation deadlock. run_inline_tool_loop called execute_tool_call_erased sequentially without draining elicitation_rx, causing deadlock when an MCP tool sent an elicitation event and blocked waiting for a response. - Change run_inline_tool_loop to &mut self - Wrap each execute_tool_call_erased call in tokio::select! that concurrently drains elicitation_rx and calls handle_elicitation_event - Change handle_elicitation_event to pub(super) for cross-module access - Add regression test with blocking executor that simulates the real MCP deadlock scenario; test times out in 5s if deadlock recurs
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Summary
run_inline_tool_loop(phase 3 of feat(mcp): elicitation during tool execution — phase 2 #2522)run_inline_tool_loopnow takes&mut selfand wraps eachexecute_tool_call_erasedintokio::select!that concurrently drainselicitation_rxhandle_elicitation_eventvisibility changed topub(super)for cross-module access frommod.rsRoot cause
run_inline_tool_loopcalledexecute_tool_call_erasedsequentially with no concurrent drain ofelicitation_rx. When an MCP tool sent an elicitation event and blocked waiting for a response,execute_tool_call_erasedalso blocked waiting for the tool — classic deadlock.Test plan
cargo +nightly fmt --checkpassescargo clippy --workspace -- -D warningspassescargo nextest run --workspace --lib --bins— 7055/7055 passedelicitation_event_during_tool_execution_is_handledwith a blocking executor that simulates the real MCP scenario; times out in 5s if deadlock recursinline_tool_loop_testsupdated (6 call sites:let agent→let mut agent)Closes #2542