14.04 to 16.04 LTS gcc-5-base downgrade

Question

I don't know if anyone can help me with gcc-5-base issue. Ever since I upgraded my 14.04 LTS to 16.04 LTS, I have packages with unmet dependencies.

The following packages have unmet dependencies:
libstdc++6 : Depends: gcc-5-base (= 5.4.0-6ubuntu1~16.04.2) but 5.4.1-2ubuntu1~14.04 is installed
libstdc++6:i386 : Depends: gcc-5-base:i386 (= 5.4.0-6ubuntu1~16.04.2) but it is not installed
               Depends: libc6:i386 (>= 2.18) but it is not installed
               Depends: libgcc1:i386 (>= 1:4.2) but it is not installed
E: Unmet dependencies. Try using -f.

I wanna ask if there is a way to roll-back 5.4.1-2ubuntu1 to 5.4.0-6ubuntu1. Thanks!

Answer 1

In addition to what the OP describes, my do-release-upgrade was interrupted by this issue. Josh.F's comment did the trick for me:

sudo add-apt-repository ppa:ubuntu-toolchain-r/test
sudo apt-get update
sudo apt-get -f install

That fixed gcc-5 for me and then I still needed to sudo apt-get upgrade

Answer 2

The comment by @josh-f fixed this for me:

sudo add-apt-repository ppa:ubuntu-toolchain-r/test
sudo apt-get update
sudo apt-get install -y r-base-dev

Answer 3

I had to add

deb http://cz.archive.ubuntu.com/ubuntu xenial-updates main

to /etc/apt/sources.list then

apt-get update apt-get install -f

Answer 4

The only thing that helped me was to downgrade gcc-5-base directly via the deb file:

wget http://security.ubuntu.com/ubuntu/pool/main/g/gcc-5/gcc-5-base_5.4.0-6ubuntu1~16.04.12_amd64.deb && sudo dpkg -i gcc-5-base_5.4.0-6ubuntu1~16.04.12_amd64.deb

Then doing a ppa-purge of the ubuntu-toolchain-r/test and upgrade:

sudo apt-get install -f ppa-purge && sudo ppa-purge -y ppa:ubuntu-toolchain-r/test

sudo apt-get update; sudo apt-get -y upgrade