def _warn_unawaited_coroutine(coro):
    from _warnings import warn
    msg_lines = [
        f"coroutine '{coro.__qualname__}' was never awaited\n"
    ]
    if coro.cr_origin is not None:
        import linecache, traceback
        def extract():
            for filename, lineno, funcname in reversed(coro.cr_origin):
                line = linecache.getline(filename, lineno)
                yield (filename, lineno, funcname, line)
        msg_lines.append("Coroutine created at (most recent call last)\n")
        msg_lines += traceback.format_list(list(extract()))
    msg = "".join(msg_lines).rstrip("\n")
    warn(msg, category=RuntimeWarning, stacklevel=2, source=coro)