Did you notice that on debian 9 it’s impossible by default to cut and paste with mouse on vim? Since it’s something important and comfortable, i checked how to restore this function. This is simple and here below how to do this:

Go In /usr/share/vim/vim80/defaults.vim and comment out the mouse specific detection as follows:

" In many terminal emulators the mouse works just fine. By enabling it you
" can position the cursor, Visually select and scroll with the mouse.
"if has('mouse')
" set mouse=a

please see that comments are with ” character

that’s all.