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.