def disposition_debug_msg(disp: TFileDisposition) -> str:
    """Make a nice debug message of what the FileDisposition is doing."""
    if disp.trace:
        msg = f"Tracing {disp.original_filename!r}"
        if disp.original_filename != disp.source_filename:
            msg += f" as {disp.source_filename!r}"
        if disp.file_tracer:
            msg += f": will be traced by {disp.file_tracer!r}"
    else:
        msg = f"Not tracing {disp.original_filename!r}: {disp.reason}"
    return msg
Make a nice debug message of what the FileDisposition is doing.
coverage/disposition.py