Re: [Trisquel-users] Gimp 2.8 ppa not working

[mikko . viinamaki]

First a word of warning, the ubuntu ppas could contain non-free software.  
They often also feature technically unstable versions etc. These might or  
might not be the case here.

Having said that, how did you go about the install attempt? This might work:
sudo add-apt-repository ppa:otto-kesselgulasch/gimp
sudo apt-get update
sudo apt-get upgrade