How to install g++-5 on Ubuntu 20.04?

Solution 1:

The g++-5 package is available only for Ubuntu 18.04 LTS.

To install it on 20.04 LTS you can download it and install manually by using commands below:

cd ~/Downloads
wget -c http://archive.ubuntu.com/ubuntu/pool/universe/g/gcc-5/gcc-5-base_5.5.0-12ubuntu1_amd64.deb
wget -c http://archive.ubuntu.com/ubuntu/pool/universe/i/isl-0.18/libisl15_0.18-4_amd64.deb
wget -c http://archive.ubuntu.com/ubuntu/pool/universe/g/gcc-5/cpp-5_5.5.0-12ubuntu1_amd64.deb
wget -c http://archive.ubuntu.com/ubuntu/pool/universe/g/gcc-5/libasan2_5.5.0-12ubuntu1_amd64.deb
wget -c http://archive.ubuntu.com/ubuntu/pool/universe/g/gcc-5/libmpx0_5.5.0-12ubuntu1_amd64.deb
wget -c http://archive.ubuntu.com/ubuntu/pool/universe/g/gcc-5/libgcc-5-dev_5.5.0-12ubuntu1_amd64.deb
wget -c http://archive.ubuntu.com/ubuntu/pool/universe/g/gcc-5/gcc-5_5.5.0-12ubuntu1_amd64.deb
wget -c http://archive.ubuntu.com/ubuntu/pool/universe/g/gcc-5/libstdc++-5-dev_5.5.0-12ubuntu1_amd64.deb
wget -c http://archive.ubuntu.com/ubuntu/pool/universe/g/gcc-5/g++-5_5.5.0-12ubuntu1_amd64.deb

sudo apt install ./g++-5_5.5.0-12ubuntu1_amd64.deb ./gcc-5_5.5.0-12ubuntu1_amd64.deb ./gcc-5-base_5.5.0-12ubuntu1_amd64.deb ./cpp-5_5.5.0-12ubuntu1_amd64.deb ./libisl15_0.18-4_amd64.deb ./libgcc-5-dev_5.5.0-12ubuntu1_amd64.deb ./libasan2_5.5.0-12ubuntu1_amd64.deb ./libmpx0_5.5.0-12ubuntu1_amd64.deb ./libstdc++-5-dev_5.5.0-12ubuntu1_amd64.deb