tps://askubuntu.com/questions/1229774/how-to-use-an-older-version-of-gcc"><span style=' text-decoration: underline;'>here</span></a><span>. Note that you need to install g++ (e.g. </span><span style=' font-family: monospace;'>sudo apt install g++-6</span><span>). If you are using R2017b or earlier, see </span><a href = "https://askubuntu.com/questions/1036108/install-gcc-4-9-at-ubuntu-18-04"><span style=' text-decoration: underline;'>here</span></a><span>. Then simply re-run </span><span style=' font-family