develop: AssertionError: assert self._session_complete when using phantomjs

[ivan]

From the !a https://www.madewithcode.com/# --phantomjs job:

ERROR Proxy error
Traceback (most recent call last):
  File "/home/archivebot/.local/lib/python3.5/site-packages/wpull/http/client.py", line 55, in session
    yield session
  File "/home/archivebot/.local/lib/python3.5/site-packages/wpull/proxy.py", line 88, in _process_request
    yield From(writer.drain())
  File "/home/archivebot/.local/lib/python3.5/site-packages/trollius/tasks.py", line 314, in _wakeup
    value = future.result()
  File "/home/archivebot/.local/lib/python3.5/site-packages/trollius/futures.py", line 277, in result
    raise self._exception
  File "/home/archivebot/.local/lib/python3.5/site-packages/trollius/tasks.py", line 245, in _step
    result = coro.throw(exc)
  File "/home/archivebot/.local/lib/python3.5/site-packages/trollius/streams.py", line 302, in drain
    yield From(self._protocol._drain_helper())
  File "/home/archivebot/.local/lib/python3.5/site-packages/trollius/tasks.py", line 314, in _wakeup
    value = future.result()
  File "/home/archivebot/.local/lib/python3.5/site-packages/trollius/futures.py", line 277, in result
    raise self._exception
  File "/home/archivebot/.local/lib/python3.5/site-packages/trollius/tasks.py", line 249, in _step
    result = next(coro)
  File "/home/archivebot/.local/lib/python3.5/site-packages/trollius/streams.py", line 193, in _drain_helper
    raise ConnectionResetError('Connection lost')
ConnectionResetError: Connection lost
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
  File "/home/archivebot/.local/lib/python3.5/site-packages/wpull/proxy.py", line 39, in __call__
    result = yield From(self._process_request(reader, writer))
  File "/home/archivebot/.local/lib/python3.5/site-packages/trollius/tasks.py", line 314, in _wakeup
    value = future.result()
  File "/home/archivebot/.local/lib/python3.5/site-packages/trollius/futures.py", line 277, in result
    raise self._exception
  File "/home/archivebot/.local/lib/python3.5/site-packages/trollius/tasks.py", line 245, in _step
    result = coro.throw(exc)
  File "/home/archivebot/.local/lib/python3.5/site-packages/wpull/proxy.py", line 89, in _process_request
    yield From(session.read_content(file=writer, raw=True))
  File "/opt/leakless/lib/python3.5/contextlib.py", line 77, in __exit__
    self.gen.throw(type, value, traceback)
  File "/home/archivebot/.local/lib/python3.5/site-packages/wpull/http/client.py", line 57, in session
    session.clean_up()
  File "/home/archivebot/.local/lib/python3.5/site-packages/wpull/http/client.py", line 189, in clean_up
    assert self._session_complete
AssertionError

(I think that also leads to it not doing anything.)