Hybrid Python/C engines blend asynchronous coroutines with native C threads, but the mix raises questions about how errors and console output travel between worlds. In the design outlined by Muhammed Shafin P on DEV, Python coroutines keep their familiar exception semantics: a failure inside a coroutine is captured by its Future, and awaiting that Future re‑raises the original exception at the call site. Multiple awaits see the same traceback, preserving debugging clarity.

C tasks, on the other hand, cannot raise Python exceptions directly. Instead, the engine wraps any failure in a custom CExecutionError. When Python later checks the result or waits for completion, this wrapper surfaces at the original Python call site, keeping the Non‑GIL thread safe while still offering natural error handling.

Console output from C threads bypasses Python’s buffering and streams straight to stdout. Developers should expect interleaved prints when several threads write simultaneously, but the real‑time feedback can aid progress logging. Together, these rules guarantee that Python code remains predictable, C threads stay isolated, and developers see immediate logs without sacrificing safety.