can't uninstall an enditable pip package

I installed a smbus2 package as editable,

pip install -e ./smbus2-0.1.4

Now I want to uninstall it but can't. Here is what I'm getting when I uninstall it,

$ pip uninstall smbus2
Can't uninstall 'smbus2'. No files were found to uninstall.

Here is the output of pip show --files smbus2

Name: smbus2
Version: 0.1.4
Location: /home/pi/projects/smbus2-0.1.4
Requires:
Files:
Cannot locate installed-files.txt

What do I need to do to uninstall it and let pip know that it is uninstalled?

EDIT

$ pip --version
pip 1.5.6 from /usr/lib/python2.7/dist-packages (python 2.7)