Summary

In prompt_toolkit 3.0.52, run_in_terminal() is a regular function that returns an asyncio.Future (via ensure_future). Discarding the return value lets Python GC it without ever calling result(), which in Python 3.12+ fires "coroutine was never awaited" RuntimeWarnings that bubble into process_loop exception handler and get logged as process_loop unhandled error.

Root Cause

_schedule_run_in_terminal() checked asyncio.iscoroutinefunction(run_in_terminal) — which is False for pt 3.0.52 (it is a sync function that internally wraps a coroutine). So the else branch called run_in_terminal(callback) and discarded the returned Future.

The callback did execute (it was already scheduled via ensure_future), but the discarded Future triggered the GC warning.

Fix

Capture the return value from run_in_terminal(callback) and, if it is an asyncio.Future, attach a no-op done_callback so the Future is properly collected without warnings.

Impact

• Eliminates the "coroutine was never awaited" warning and the subsequent "process_loop unhandled error" log message
• No behavioral change — the callback still executes as before
• Affects /new, /clear, /reset, and any other slash command that triggers cross-thread printing via _cprint() during session transitions