pip install - killed
If you are running low on memory you could try with
pip install package --no-cache-dir
You have to check logs, depending on the version of ubuntu and stuff, it should be in
/var/log/messages or at least in
/var/log so you can grep python or pip in that folder. This should provide hints.
Also, if you're not in a virtualenv, you should probably use
sudo to perform (implicit) privileged operations, such as copying the library in the global lib folder.