Currently portage uses its internal EventLoop implementation in threads and child processes. It would be better if the default asyncio event loop implementation could be used instead, in order to support new features such as PEP 525 asynchronous generators. For forks, hopefully https://bugs.python.org/issue22087 can suppressed by instantiating a new event loop in the subprocess, which is supported since https://bugs.python.org/issue29703 was fixed.