手元の 20.04 に GCC (g++) をインストールしようとしたら、見慣れないエラーが出てきました。 $ sudo apt install gcc g++ make 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 Inco