I installed vim-flake8 by git cloning it on my Pathogen bundle folder as usual, but when I tried to run the plugin pressing F7 or using :call Flake8() in one Python file I receive the following message:
Error detected while processing function Flake8:
line 8:
File flake8 not found. Please install it first.
Anyone has some clue about what is going on ?
The error message is telling you that you didn't install the program flake8. Install it.
Assuming pip is installed
pip install flake8
should work.