ipython crashes on ctrl-c

[jchayat]

Hi all,

I'm using Ipython (0.12 or 0.13 - same problem) under bash in Ubuntu 12.04 Desktop 64-bit.

I'm trying to use neo4j-embedded (a version of neo4j graph database that's embedded in python), It uses jpype.
after I import neo4j, if i press UP (for line history) and then crtl-c to clear the line then Ipython crashes in a wierd way.
It returns to console but text is not displayed anymore (but it is still possible to execute commands - text just not displayed).
also ENTER stops breaking the line, it just causes the prompt to be reprinted (at the end of the line)

this happens only after I import neo4j, but I still post it here in ipython since it is a shell issue,

Jon

[fperez]

Does this also happen if you do it in nomal python (not ipython), but where you first run import rlcompleter? That would help us know if it's a readline interaction or not.

Also, can you test if it happens when using the qtconsole or the notebook?

[jbruck]

I have a similar issue. I'm on Windows 7 32bit, I installed python xy, but have subsequently upgraded to ipython 0.13

Ipython crashes when I press ctrl_c from the command prompt (and in windows powershell).

Standard python does not crash on import rlcompleter and the qtconsole and notebook do not crash either.

[takluyver]

@jbruck : My instinct is that that's a different problem - you're on a different platform and you don't mention using neo4j. Can you file a separate issue for it, with a copy of any error message or traceback you get?

[shawnlower]

Yes, I'm having the same issue here, and it affects both iPython (0.12.1) and CPython (2.7.3-0ubuntu3.1).

I suppose that means I should be reporting the bug with neo4j?

I was able to workaround it by restoring the signal handler after importing neo4j. Example:

#########################################################################

Crashy behavior:

shawn@carbon:~/Download/neo4j-community-1.8$ ipython

In [1]: from neo4j import GraphDatabase

In [2]: shawn@carbon:~/Download/neo4j-community-1.8$ 130
shawn@carbon:~/Download/neo4j-community-1.8$ shawn@carbon:~/Download/neo4j-community-1.8$ 
shawn@carbon:~/Download/neo4j-community-1.8$ 

#########################################################################

Control-C was pressed at [2]. Afterward I ran 'echo $?', to show the return code of 130, and 'stty echo' to fix the terminal ('reset' would also work).

#########################################################################

With rlcompleter:

shawn@carbon:~/Download/neo4j-community-1.8$ python
Python 2.7.3 (default, Aug  1 2012, 05:16:07) 
[GCC 4.6.3] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import rlcompleter
>>> from neo4j import GraphDatabase
>>> shawn@carbon:~/Download/neo4j-community-1.8$ 

#########################################################################

Fixed behavior:

shawn@carbon:~/Download/neo4j-community-1.8$ ipython

In [1]: from neo4j import GraphDatabase

In [2]: import signal

In [3]: signal.signal(signal.SIGINT, signal.default_int_handler)
Out[3]: <function signal.default_int_handler>

In [4]: 
KeyboardInterrupt

In [4]: 

#########################################################################

For reference, here are a few of the other package versions:

• neo4j-community-1.8
• JPype==0.5.4.2 (via pip)
• openjdk-6-jre-headless 6b24-1.11.4-1ubuntu0.12.04.1 i386

[minrk]

From my reading, this is a neo4j issue, registering a signal handler. IPython should probably not protect against this sort of thing.