I have the same problem but did not manage to sort it by looking for different versions of pip.
Could you elaborate a little on how you went about solving it?
My 'whereis pip' gives:
pip: /usr/bin/pip /home/jakob/.local/bin/pip2.7 /home/jakob/.local/bin/pip /usr/share/man/man1/pip.1.gz
As far as I can tell they are all v. 9.0.3
Probably related is that the most recent pip version 10.0.1 breaks something with the same ImportError as here, which is why I am using 9.0.3 instead.
I supposed the Build is installing a separate pip which it then wishes to downgrade to 1.4.1, but due to the latest version breaking things, this issue emerges.
I would much appreciate a hint
Thanks in advance