asyncsub.py: buffer() was removed in Python 3
- https://portingguide.readthedocs.io/en/latest/etc.html#raw-buffer-protocol-buffer-and-memoryview
- https://docs.python.org/2/library/functions.html#buffer
- https://docs.python.org/2/c-api/buffer.html
- https://docs.python.org/3/c-api/buffer.html
./morituri/extern/asyncsub.py:160:16: F821 undefined name 'buffer'
data = buffer(data, sent)
^