The fix seems to be simple: skip the test if write() fails with errno.ENOSPC: "OSError: [Errno 28] No space left on device".


AMD64 Windows7 SP1 3.x:
https://buildbot.python.org/all/#/builders/40/builds/2628

======================================================================
ERROR: test_large_file_ops (test.test_io.CIOTest)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "C:\buildbot.python.org\3.x.kloth-win64\build\lib\test\test_io.py", line 608, in test_large_file_ops
    self.large_file_ops(f)
  File "C:\buildbot.python.org\3.x.kloth-win64\build\lib\test\test_io.py", line 389, in large_file_ops
    self.assertEqual(f.write(b"xxx"), 3)
OSError: [Errno 28] No space left on device

======================================================================
ERROR: test_large_file_ops (test.test_io.PyIOTest)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "C:\buildbot.python.org\3.x.kloth-win64\build\lib\test\test_io.py", line 608, in test_large_file_ops
    self.large_file_ops(f)
  File "C:\buildbot.python.org\3.x.kloth-win64\build\lib\test\test_io.py", line 389, in large_file_ops
    self.assertEqual(f.write(b"xxx"), 3)
  File "C:\buildbot.python.org\3.x.kloth-win64\build\lib\_pyio.py", line 1698, in write
    return os.write(self._fd, b)
OSError: [Errno 28] No space left on device


No idea if the following test_asyncio failure is related.

======================================================================
ERROR: test_huge_content (test.test_asyncio.test_sock_lowlevel.SelectEventLoopTests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "C:\buildbot.python.org\3.x.kloth-win64\build\lib\test\test_asyncio\test_sock_lowlevel.py", line 170, in test_huge_content
    self.loop.run_until_complete(
  File "C:\buildbot.python.org\3.x.kloth-win64\build\lib\asyncio\base_events.py", line 608, in run_until_complete
    return future.result()
  File "C:\buildbot.python.org\3.x.kloth-win64\build\lib\test\test_asyncio\test_sock_lowlevel.py", line 157, in _basetest_huge_content
    data = await self.loop.sock_recv(sock, DATA_SIZE)
  File "C:\buildbot.python.org\3.x.kloth-win64\build\lib\asyncio\selector_events.py", line 362, in sock_recv
    return await fut
  File "C:\buildbot.python.org\3.x.kloth-win64\build\lib\asyncio\selector_events.py", line 373, in _sock_recv
    data = sock.recv(n)
ConnectionResetError: [WinError 10054] An existing connection was forcibly closed by the remote host