I am trying to install gcc (in order to install postGIS later), but i have the folowing problem (you can see in the picture). Can anyone help?

I am trying to install gcc (in order to install postGIS later), but i have the folowing problem (you can see in the picture). Can anyone help?

You can get a list of actually held packages with:
dpkg --get-selections | grep hold
If there are none, or none look related, then it's probably something else. You can also try using the aptitude rather than apt-get to install your package:
sudo aptitude install <packagename>
Aptitude will try and find solutions which involve modifying other packages. It will also give you a detailed explanation of the problem and options for fixing it.
If you try Aptitude with -f, it will change its priorities and then you will obtain only those solutions which require removing/downgrading fewer packages. Here's the command:
sudo aptitude -f install <packagename>
Note: Assuming dpkg --get-selections | grep hold is empty, Aptitude is your best solution to resolve held packages.
Source URL: Unable to correct problems, you have held broken packages