Pip stdout info incorrectly recognizing installed version

[keshavchintamani]

• Pip version: 8.11
• Python version: 2.7.2
• Operating system: Ubuntu 16.04

Description:

This is not a critical issue, maybe a cache bug somewhere. Pip was telling me to upgrade to 9.0.1 but after a successful install, it says I'm still on 8.1.1 although checking pip --version says 9.0.1

What I've run:

Successfully installed rosinstall-generator-0.1.13
You are using pip version 8.1.1, however version 9.0.1 is available.
You should consider upgrading via the 'pip install --upgrade pip' command.
kc@kc:~/sandbox$ pip install --upgrade pip
Collecting pip
  Using cached pip-9.0.1-py2.py3-none-any.whl
Installing collected packages: pip
Successfully installed pip-8.1.1
You are using pip version 8.1.1, however version 9.0.1 is available.
You should consider upgrading via the 'pip install --upgrade pip' command.
kc@kc:~/sandbox$ pip --version
pip 9.0.1 from /home/kc/.local/lib/python2.7/site-packages (python 2.7)

[xavfernandez]

Hopefully it was fixed in #3723.
If you're still facing the issue in pip 9.0.1, please re-open an issue with reproduction steps.