same thing - ‘Error: /lib/x86_64-linux-gnu/libstdc++.so.6: version `GLIBCXX_3.4.30’ not found’
ubuntu 20.04.6
apt upgrade does not effects.
last vertion of this lib in the system for now is GLIBCXX_3.4.28
UPD:
fixed only with all these commands:
sudo add-apt-repository ppa:ubuntu-toolchain-r/test
sudo apt-get update
sudo apt-get upgrade
sudo apt-get dist-upgrade
dist-upgrate install GLIBCXX_3.4.30 up to GLIBCXX_3.4.32 for me on ubuntu 20.04