Issue about python-cmd2

Running stack.sh on a clean Ubuntu machine will lead to message like:
Installed /usr/local/lib/python2.7/dist-packages/tablib-0.9.11-py2.7.egg
Searching for cmd2
Reading http://pypi.python.org/simple/cmd2/
Reading http://www.assembla.com/wiki/show/python-cmd2
Reading https://sourceforge.net/projects/python-cmd2
Reading http://packages.python.org/cmd2/
Reading http://catherine.devlin.googlepages.com/cmd2.html
error: Connection reset by peer
++ failed
++ local r=1
++ set +o xtrace

After I run sudo apt-get install python-cmd2, this will be removed. It seems that maybe there is any issue about the installation of cmd2.