ipython crash

[thisgf]

Traceback (most recent call last):
  File "c:\python27\lib\runpy.py", line 162, in _run_module_as_main
    "__main__", fname, loader, pkg_name)
  File "c:\python27\lib\runpy.py", line 72, in _run_code
    exec code in run_globals
  File "C:\Python27\Scripts\ipython.exe\__main__.py", line 9, in <module>
    sys.exit(start_ipython())
  File "c:\python27\lib\site-packages\IPython\__init__.py", line 119, in start_i
python
    return launch_new_instance(argv=argv, **kwargs)
  File "c:\python27\lib\site-packages\traitlets\config\application.py", line 658
, in launch_instance
    app.start()
  File "c:\python27\lib\site-packages\IPython\terminal\ipapp.py", line 348, in s
tart
    self.shell.mainloop()
  File "c:\python27\lib\site-packages\IPython\terminal\interactiveshell.py", lin
e 440, in mainloop
    self.interact()
  File "c:\python27\lib\site-packages\IPython\terminal\interactiveshell.py", lin
e 423, in interact
    code = self.prompt_for_code()
  File "c:\python27\lib\site-packages\IPython\terminal\interactiveshell.py", lin
e 333, in prompt_for_code
    pre_run=self.pre_prompt, reset_current_buffer=True)
  File "c:\python27\lib\site-packages\prompt_toolkit\interface.py", line 392, in
 run
    self._redraw()
  File "c:\python27\lib\site-packages\prompt_toolkit\interface.py", line 351, in
 _redraw
    self.renderer.render(self, self.layout, is_done=self.is_done)
  File "c:\python27\lib\site-packages\prompt_toolkit\renderer.py", line 398, in
render
    size = output.get_size()
  File "c:\python27\lib\site-packages\prompt_toolkit\terminal\win32_output.py",
line 103, in get_size
    info = self.get_win32_screen_buffer_info()
  File "c:\python27\lib\site-packages\prompt_toolkit\terminal\win32_output.py",
line 150, in get_win32_screen_buffer_info
    raise NoConsoleScreenBufferError
NoConsoleScreenBufferError: No Windows console found. Are you running cmd.exe?

os:win7 64bit
python version:2.7

[minrk]

How did you start IPython?

[thisgf]

1.window+r open run popup window and input ipython
2. cmd window input ipython
both will crash

[takluyver]

Are you using the standard Windows cmd, or is there anything unusual about it?

@jonathanslenders may have more ideas.

[jonathanslenders]

So, you type "ipython" in the run dialog? Does it work if you type "cmd" in the run dialog and then "ipython" in the window? I guess that in some situations this could start an IPython process without a console attached. The weird thing is that I'm unable to reproduce it.

@thisgf: Which Windows version are you using?

Related pull request: prompt-toolkit/python-prompt-toolkit#396 can allocate a windows console if none is available. I'm not sure however whether that would work in this case. Maybe calling AllocConsole (win32 api) could do the trick.

[takluyver]

@jonathanslenders : Another instance of this has shown up, with @omri7 on #10109. They have Python 2.7.6 on Windows 10. Hopefully that helps work out the issue.

[jonathanslenders]

This remains a mystery...
I have now Windows 10, and just installed Python 2.7.6 (32bit), IPython 5.1.0. Everything runs fine.

@thisgf @omri7: could you share a screenshot with the actual output? Maybe that could explain something. Further, can you give me the output of sys.maxsize?

[omri7]

Sure:
(Win10, 64bit)

In [1]: import sys

In [2]: sys.maxsize
Out[2]:
9223372036854775807L

[jonathanslenders]

This looks like a 64bit build of Python. Maybe that could be the reason...?

[jonathanslenders]

That's it, I can reproduce it! :-) Probably all 64bit builds of Python 2.7 on Windows have this issue. 32bit runs fine.
Now looking for a solution.

[omri7]

Cool :)

[jonathanslenders]

So, I have a possible solution, but it's super weird.

In the following file: https://github.com/jonathanslenders/python-prompt-toolkit/blob/master/prompt_toolkit/terminal/win32_output.py

Replace the get_win32_screen_buffer_info function by this:

    def get_win32_screen_buffer_info(self):
        sbinfo = CONSOLE_SCREEN_BUFFER_INFO()
        self.flush()
        success = windll.kernel32.GetConsoleScreenBufferInfo(
                               self.hconsole, byref(sbinfo))
        
        if success:
            return sbinfo
        else:
            raise NoConsoleScreenBufferError

That seems to work (at least for me.)

Now, on the other hand, if we do the following. Then the rendering is not correct, the cursor doesn't appear on the right places, and some output is duplicated when accepting inputs.

   def _test(self, func, console, sbinfo):
        " Additional method. "
        self.flush()
        success = func(console, sbinfo)
        return success
        
    def get_win32_screen_buffer_info(self):
        sbinfo = CONSOLE_SCREEN_BUFFER_INFO()
        success = self._test(windll.kernel32.GetConsoleScreenBufferInfo, self.hconsole, byref(sbinfo))
     
        if success:
            return sbinfo
        else:
            raise NoConsoleScreenBufferError

Further, with keyword arguments, it crashes with the NoConsoleScreenBufferError:

   def _test(self, func, *a):
        " Additional method. "
        self.flush()
        success = func(*a)
        return success
        
    def get_win32_screen_buffer_info(self):
        sbinfo = CONSOLE_SCREEN_BUFFER_INFO()
        success = self._test(windll.kernel32.GetConsoleScreenBufferInfo, self.hconsole, byref(sbinfo))
     
        if success:
            return sbinfo
        else:
            raise NoConsoleScreenBufferError

Try to understand that... I also had a variation where it crashed sometimes, but not always.

[jonathanslenders]

I pushed a possible fix: prompt-toolkit/python-prompt-toolkit@d5d9e29

Everyone: can you please upgrade to the latest prompt_toolkit master, and see whether it works?
So far, I really still don't understand what's going on. I'm far from confident, but for IPython it seems to work stable, where I got a crash before.