Terminal windows exits on Windows 10 build 17692

[melund]

I am having problems with prompt-toolkit 1 after getting the newest update to Windows (Insiders slow ring build 17692).

Both xonsh (#2703) and ptpython with ptk1 causes the terminal window to exit when I start the programs. No error messages or anything. The conhost terminal window just disappears.

I haven't tried to debug this yet, to see when it happens. But I will try it this weekend.

I would really love to see if this is a problem with PTK 2 as well. Is there any application I could try to test that?

[melund]

I have just tried IPython and ptpython with PTK2 as well.

Unfortunately, the same behaviour. Terminal window just shuts down.

I guess this is most likely a bug in the console on Windows. So maybe I should also report it here: https://github.com/Microsoft/console/issues

@jonathanslenders Any pointers to how I can best help solve and debug it before we report it to the console team?

[scopatz]

That is not good. Maybe that console repo is the right place to bring it up.

[melund]

I was wrong about PTK2. Conda downgraded prompt_toolkit when I installed IPython, without me noticing. So it does work with PTK2 :)

[scopatz]

Ahh that is good to know!

[melund]

@jonathanslenders Here is some more debug info.

The crash happens when the PTK1 tries to call _erase()

The following is as close I could debug before the terminal disappears.

(Pdb) where
  c:\users\mel\documents\scratch\ptpython\debug.py(2)<module>()
-> run()
  c:\users\mel\documents\scratch\ptpython\ptpython\entry_points\run_ptpython.py(71)run()
-> title='Python REPL (ptpython)')
  c:\users\mel\documents\scratch\ptpython\ptpython\repl.py(315)embed()
-> cli.run()
  c:\users\mel\anaconda3\lib\site-packages\prompt_toolkit\interface.py(400)run()
-> assert pre_run is None or callable(pre_run)
  c:\users\mel\anaconda3\lib\site-packages\prompt_toolkit\interface.py(358)_redraw()
-> self.renderer.render(self, self.layout, is_done=self.is_done)
  c:\users\mel\anaconda3\lib\site-packages\prompt_toolkit\renderer.py(450)render()
-> previous_width=(self._last_size.columns if self._last_size else 0))
  c:\users\mel\anaconda3\lib\site-packages\prompt_toolkit\renderer.py(128)_output_screen_diff()
-> output.erase_down()
  c:\users\mel\anaconda3\lib\site-packages\prompt_toolkit\terminal\win32_output.py(200)erase_down()
-> self._erase(start, length)
  c:\users\mel\anaconda3\lib\site-packages\prompt_toolkit\terminal\win32_output.py(216)_erase()
-> byref(chars_written))
> c:\users\mel\anaconda3\lib\site-packages\prompt_toolkit\terminal\win32_output.py(135)_winapi()
-> return func(*a, **kw)

I also captured the debug render info from the _winapi() wrapper.

b"'FillConsoleOutputCharacterA'\n"
b"     68, c_char(b' '), c_ulong(1076400), c_long(2031616), <cparam 'P' (000002D942529A10)>\n"
b"     <class 'int'>, <class 'ctypes.c_char'>, <class 'ctypes.c_ulong'>, <class 'ctypes.c_long'>, <class 'CArgObject'>\n"

Hope this helps you a bit.

[melund]

Ahh that is good to know!

@scopatz Yes. The best fix in xonsh is probably to upgrade to PTK 2. But I hope IPython will also follow soon. Otherwise, it will be a little annoying.

[jonathanslenders]

@melund, thank you for debugging this so far!
The reason that PTK 2 doesn't crash is probably because it detects that the Windows console now supports ANSI escape sequences, and it will output that instead.

I hope to find some time this weekend to debug it.

IPython merged a patch for PTK 2 support, so I think the next (major) release will include it.

[melund]

IPython merged a patch for PTK 2 support, so I think the next (major) release will include it.

Thanks for letting us know. That is great. @scopatz timing xonsh support for ptk2 with the IPython release would probably be a good idea. Unless we plan to support both versions.

[jonathanslenders]

I have some issues upgrading to the latest Windows 10. (see screenshot below...) If someone has some time to debug this bug above, that would be great. I'll see whether I can fix my PC in the meantime.

--

[jonathanslenders]

So I managed to update.

While working on pymux, in certain situations, I could make the console window crash as well, but only after running my server/client experiment, detaching the pymux client, waiting until the Python process is finished, and then typing "ls" would make the console window close. Very weird. I wonder whether that's a bug in Windows, or whether I'm leaving the console in a bad state.
I can't reproduce it however with simple PTK prompts, those work fine here...

[melund]

I can't reproduce it however with simple PTK prompts, those work fine here...

That is great to hear. My Windows installation just updated to build 17713.rs5, and that has solved the problem for me as well.

[melund]

Unless @jonathanslenders has any objections I think I will close this issue.

[jonathanslenders]

That's fine. Thanks! We'll open again if needed.