fix(voice): prevent rdev TSMGetInputSourceProperty crash on macOS 26

[M3gA-Mind]

Summary

• Root cause: rdev's CGEventTap callback invokes TSMGetInputSourceProperty from the voice-hotkey background thread. macOS 26 enforces dispatch_assert_queue(main_queue) inside that API; the process is killed with EXC_BREAKPOINT (dispatch_assert_queue_fail) on the first key press after the dictation listener arms.
• dictation_listener.rs: skip the rdev listener entirely on macOS. The Tauri host already registers the shortcut via tauri-plugin-global-shortcut (main-thread-safe) and emits dictation://toggle to the frontend, making the core-side rdev listener redundant.
• server.rs: return an explicit error for non-Fn hotkeys in the voice server on macOS, preventing the same crash when the voice server is started with a key other than Fn (the Fn/Globe key is safe via the existing Swift globe listener).

Test plan

• Two new #[cfg(target_os = "macos")] async tests in dictation_listener.rs verify start_if_enabled is a no-op on macOS (with both a regular key and the Fn key) and that LISTENER_HANDLE remains None
• All 17 existing dictation listener tests pass
• All voice hotkey unit tests pass
• cargo check passes on macOS (current platform)
• cargo fmt --check passes

Note: Pre-push hook flagged pre-existing ESLint/Rust warnings in BootCheckGate.tsx and meet_audio/listen_capture.rs (code unrelated to this fix); pushed with --no-verify per CONTRIBUTING.md guidance.

Closes #2677

Summary by CodeRabbit

• Bug Fixes

  • Fixed macOS crashes by disabling unsupported hotkey listener initialization.
  • Improved error messaging to clarify which hotkeys are supported on macOS.

• Documentation

  • Clarified macOS hotkey support limitations: only the Fn/Globe key is supported; all other keys are unsupported.

[coderabbitai]

📝 Walkthrough

Walkthrough

This PR addresses a macOS 26 crash by disabling the rdev hotkey listener on macOS and extracting platform-specific code into conditional compilation blocks. Documentation and error messages are expanded to clarify that only the Fn/Globe key is supported on macOS (via Swift), and why other hotkeys are unsafe.

Changes

macOS hotkey listener no-op and rdev extraction

Layer / File(s)	Summary
dictation_listener: conditional no-op and rdev extraction src/openhuman/voice/dictation_listener.rs	start_if_enabled documentation explains macOS 26's TSMGetInputSourceProperty main-queue enforcement and why rdev is disabled. Function returns immediately on macOS via conditional compilation, while non-macOS rdev setup is extracted into a private start_rdev_listener helper. Tests verify the listener does not start on macOS even with valid hotkey values.
server.rs: documentation and error messaging src/openhuman/voice/server.rs	Comments clarify the Swift-based globe listener for Fn/Globe key handling on macOS and document the main-queue constraint. Error message for unsupported hotkeys is expanded to state only hotkey = "fn" is safe. Non-macOS rdev code is explicitly placed behind #[cfg(not(target_os = "macos"))].

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~12 minutes

Poem

🐰 A rabbit hops through platform gates,
On macOS one, the listener waits—
"Swift globe takes the call," we say,
"rdev must stay far away!"
Main thread enforced, no crash today! ✨

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title accurately describes the primary fix: preventing the rdev TSMGetInputSourceProperty crash on macOS 26 by disabling the redundant rdev listener on that platform.
Linked Issues check	✅ Passed	Changes directly address issue #2677 by preventing rdev from running on macOS (primary mitigation), returning explicit errors for non-Fn hotkeys, and adding macOS-specific tests verifying the no-op behavior.
Out of Scope Changes check	✅ Passed	All changes in both files are scoped to the macOS crash fix: conditional compilation guards for rdev, documentation updates explaining the Swift globe listener, and macOS-only test additions.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%.
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.

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[M3gA-Mind]

Code Review — PR #2735

fix(voice): prevent rdev TSMGetInputSourceProperty crash on macOS 26

Overview

Fixes a EXC_BREAKPOINT crash on macOS 26 caused by rdev's CGEventTap callback invoking TSMGetInputSourceProperty off the main thread. Two-part fix: (1) skip the rdev listener entirely on macOS via #[cfg] gates, (2) return an explicit error for non-Fn hotkeys in server.rs.

What Passed ✅

• Root cause and fix are well-documented with inline comments referencing issue Crash: dictation hotkey listener calls TSMGetInputSourceProperty off main thread (rdev / macOS 26) #2677
• Clean #[cfg(target_os = "macos")] / #[cfg(not(target_os = "macos"))] gating — compile-time safety, no runtime branches
• start_rdev_listener extraction is correct factoring
• Two new macOS no-op tests cover the primary fix path
• Existing 17 tests continue to cover non-macOS behaviour on Linux CI
• All CI checks green ✅

Recommendations

• Optional: Add a macOS-only unit test for start_hotkey_listener returning Err on non-Fn keys (e.g. "ctrl+space") to pin the server.rs error path — mirrors the dictation listener test pattern. Not a blocker.
• Note: The two macOS tests share the process-global LISTENER_HANDLE; low risk here since the function returns immediately, but worth noting for future parallel test runs.

Verdict: Approve ✅ — Correct, well-scoped crash fix with appropriate test coverage.

[M3gA-Mind]

PR Review — fix(voice): prevent rdev TSMGetInputSourceProperty crash on macOS 26

Status: ✅ All CI checks passing.

What this PR does

Fixes a process crash (EXC_BREAKPOINT / dispatch_assert_queue_fail) on macOS 26 where rdev's CGEventTap callback calls TSMGetInputSourceProperty off the main dispatch thread. The fix skips the rdev listener entirely on macOS in dictation_listener.rs (the Tauri host already handles the shortcut via tauri-plugin-global-shortcut) and returns an explicit error for non-Fn hotkeys in server.rs.

Code quality

• ✅ #[cfg(target_os = "macos")] early return in start_if_enabled is clean and well-placed
• ✅ start_rdev_listener correctly extracted behind #[cfg(not(target_os = "macos"))] — avoids dead-code warnings on macOS builds
• ✅ Comment fix in start_rdev_listener: "CmdOrCtrl → ctrl on non-macOS" is now correct since the function is non-macOS-only
• ✅ server.rs error path is informative and actionable for the caller
• ✅ Two new #[cfg(target_os = "macos")] tests confirm LISTENER_HANDLE stays None on macOS

No issues found

The change is minimal (87 additions, 9 deletions across 2 files), correct on both macOS and non-macOS, and well-tested. No performance or security concerns. Recommend merge.

[graycyrus]

Great fix for the macOS 26 crash. The approach is clean: skip rdev entirely on macOS (Tauri host handles it), return an explicit error for unsupported hotkeys. The tests verify the no-op behavior, and all CI gates pass.

Summary

dictation_listener.rs

• Adds comprehensive doc comment explaining the TSMGetInputSourceProperty dispatch queue issue
• Platform guard: early return on macOS, defers to Tauri host
• Extracts rdev startup to start_rdev_listener() wrapped in #[cfg(not(target_os = "macos"))]
• Two new macOS tests verify start_if_enabled is a no-op and LISTENER_HANDLE remains None

server.rs

• Updates doc to clarify Fn/Globe is the only supported hotkey on macOS
• Returns explicit, actionable error for non-Fn keys: "only 'fn' (Fn/Globe key) is safe... Set hotkey = "fn" in voice config"
• Wraps rdev path in #[cfg(not(target_os = "macos"))] guard

Verification

• Closes #2677 as intended
• Issue/PR alignment: ✓ (uses fix #1 from issue: switch to main-thread-safe alternative)
• CI: all green across coverage, quality, e2e, smoke tests
• No CodeRabbit findings to address
• Test coverage: existing dictation + voice tests all pass, plus two new macOS-specific tests

LGTM. Ready to merge.