ipython notebook freeze on start - ipython

Question

my ipython notebook functionality stop working.
If I do
ipython notebook
the console just hangs forever with no debug output.
I have already tried reinstalling ipython but no success.
Also, if I start normal ipython everything seems fine.
Does anybody have a clue how to solve this? I suspect some lock file is still there but how can I find out what is exactly going wrong?
also if I force interrupt I get the following stack trace
^C^CTraceback (most recent call last):
File "/home/lfiaschi/anaconda/bin/ipython", line 9, in <module>
load_entry_point('ipython==1.2.1', 'console_scripts', 'ipython')()
File "/home/lfiaschi/anaconda/lib/python2.7/site-packages/IPython/__init__.py", line 118, in start_ipython
return launch_new_instance(argv=argv, **kwargs)
File "/home/lfiaschi/anaconda/lib/python2.7/site-packages/IPython/config/application.py", line 544, in launch_instance
app.initialize(argv)
File "<string>", line 2, in initialize
File "/home/lfiaschi/anaconda/lib/python2.7/site-packages/IPython/config/application.py", line 89, in catch_config_error
return method(app, *args, **kwargs)
File "/home/lfiaschi/anaconda/lib/python2.7/site-packages/IPython/terminal/ipapp.py", line 312, in initialize
super(TerminalIPythonApp, self).initialize(argv)
File "<string>", line 2, in initialize
File "/home/lfiaschi/anaconda/lib/python2.7/site-packages/IPython/config/application.py", line 89, in catch_config_error
return method(app, *args, **kwargs)
File "/home/lfiaschi/anaconda/lib/python2.7/site-packages/IPython/core/application.py", line 373, in initialize
self.parse_command_line(argv)
File "/home/lfiaschi/anaconda/lib/python2.7/site-packages/IPython/terminal/ipapp.py", line 307, in parse_command_line
return super(TerminalIPythonApp, self).parse_command_line(argv)
File "<string>", line 2, in parse_command_line
File "/home/lfiaschi/anaconda/lib/python2.7/site-packages/IPython/config/application.py", line 89, in catch_config_error
return method(app, *args, **kwargs)
File "/home/lfiaschi/anaconda/lib/python2.7/site-packages/IPython/config/application.py", line 474, in parse_command_line
return self.initialize_subcommand(subc, subargv)
File "<string>", line 2, in initialize_subcommand
File "/home/lfiaschi/anaconda/lib/python2.7/site-packages/IPython/config/application.py", line 89, in catch_config_error
return method(app, *args, **kwargs)
File "/home/lfiaschi/anaconda/lib/python2.7/site-packages/IPython/config/application.py", line 405, in initialize_subcommand
subapp = import_item(subapp)
File "/home/lfiaschi/anaconda/lib/python2.7/site-packages/IPython/utils/importstring.py", line 42, in import_item
module = __import__(package, fromlist=[obj])
File "/home/lfiaschi/anaconda/lib/python2.7/site-packages/IPython/html/notebookapp.py", line 64, in <module>
from .services.kernels.kernelmanager import MappingKernelManager
File "/home/lfiaschi/anaconda/lib/python2.7/site-packages/IPython/html/services/kernels/kernelmanager.py", line 21, in <module>
from IPython.kernel.multikernelmanager import MultiKernelManager
File "/home/lfiaschi/anaconda/lib/python2.7/site-packages/IPython/kernel/__init__.py", line 6, in <module>
from .connect import *
File "/home/lfiaschi/anaconda/lib/python2.7/site-packages/IPython/kernel/connect.py", line 39, in <module>
from IPython.utils.localinterfaces import LOCALHOST
File "/home/lfiaschi/anaconda/lib/python2.7/site-packages/IPython/utils/localinterfaces.py", line 43, in <module>
PUBLIC_IPS = socket.gethostbyname_ex(socket.gethostname() + '.local')[2]
KeyboardInterrupt

Answer 1

I had the same problem in Linux/Ubuntu. This also hanged spyder.
Workaround for me:
(1) Look at host name of computer
cat /etc/hostname
which gives e.g. my-laptop
(2) Ensure that /etc/hosts contains the following entry
127.0.0.1 my-laptop my-laptop.local
because ipython looks for a 'local' extension too.
And fire up again ipython notebook or spyder. This worked for me for spyder, when it was hanging at:
PUBLIC_IPS = socket.gethostbyname_ex(socket.gethostname() + '.local')[2]