I am trying to follow instruction presented here: How to install GCC 5 on debian jessie 8.1
but I am getting this error:
sudo apt-get install -t testing gcc
Reading package lists... Done
Building dependency tree
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:
The following packages have unmet dependencies:
gsettings-desktop-schemas : Breaks: gnome-settings-daemon (< 3.19.92) but 3.14.2-3 is to be installed
Breaks: mutter (< 3.19.92) but 3.14.4-1~deb8u1 is to be installed
gstreamer1.0-plugins-base : Breaks: gstreamer1.0-plugins-bad (< 1.7.90) but 1.4.4-2.1+deb8u1 is to be installed
libgstreamer-plugins-base1.0-0 : Breaks: gstreamer1.0-plugins-bad (< 1.7.1) but 1.4.4-2.1+deb8u1 is to be installed
libpam-systemd : Depends: systemd (= 215-17+deb8u6) but 232-15 is to be installed
libvlccore8 : Breaks: vlc (< 2.2.4-7~) but 2.2.4-1~deb8u1 is to be installed
Breaks: vlc-nox (< 2.2.4-7~) but 2.2.4-1~deb8u1 is to be installed
systemd-sysv : Depends: systemd (= 215-17+deb8u6) but 232-15 is to be installed
task-cinnamon-desktop : Depends: cinnamon-desktop-environment but it is not going to be installed
E: Error, pkgProblemResolver::Resolve generated breaks, this may be caused by held packages.
What is the problem and how I can fix it?