I have the same problem stated here How can I repair my system if I forgot to remove the Gimp registry plugin when using Gimp 2.8? but it is impossible to install ppa-purge, because of the fact that ubuntu software centre doesn't work anymore saying me I've to repair the dameged packages, but when I try to do it it doesn't work...like for Leonardo.... How can i do to repair the ubuntu software centre and repair Gimp? Thanks.
Here is a method that should NOT be tried unless nothing else works...
At first wait and see if you get any other answer here...only if you dont,use this method..
In this method,we are going to delete the status entry of GIMP 2.8(Thus bypassing dpkg)
NOTE:The status file is an utterly importatnt file.In the steps given below,first we will be making a backup of the original file b4 editing for safety so that if anything goes wrong,your status file can be recovered.
Enter these commands in the terminal-
sudo cp /var/lib/dpkg/status /var/lib/dpkg/status.orig
now enter the following command to open the status file as a superuser in gedit
gksudo gedit /var/lib/dpkg/status
In the file search for a block that will start with something like this:(you may use CLTR+F to find it.just put gimp in that search box.)
Package: gimp Status: .... .... .... Original-Maintainer: Ari Pollak <firstname.lastname@example.org>
After you find it,select that complete block(Not even a single space or line more than that) and delete it.
Save the file and close it.
Then go in software sources and remove the repository.
You have successfully removed Gimp.
you can confirm it by typing in the terminal
sudo apt-get remove gimp
You should get an error saying Package not found or No such package installed
NOTE1:FOLLOW ONLY THE GIVEN INSTRUCTIONS.NOTHING EXTRA IF YOU DO NOT WANT TO SCREW UP SOMETHING ELSE.DELETING EVEN ONE LINE EXTRA IN THE STATUS FILE WILL BREAK IT AND WILL NOT LET YOU UPDATE ANYTHING AFTER THAT(Though we have created a backup file its best to take care)
NOTE2:WHEN YOU OPEN THE STATUS FILE IN GEDIT,ALONG WITH IT YOU WILL FIND ANOTHER FILE OPENING UP IN THE BACKGROUND
Untitled DocumentIGNORE IT.YOU MAY JUST CLOSE IT