sudo apt-get update
sudo apt-get install gpg wget

wget -O - https://apt.kitware.com/keys/kitware-archive-latest.asc 2>/dev/null  \
    | gpg --dearmor - | sudo tee /usr/share/keyrings/kitware-archive-keyring.gpg >/dev/null

# Ubuntu 20.04 LTS
echo 'deb [signed-by=/usr/share/keyrings/kitware-archive-keyring.gpg] https://apt.kitware.com/ubuntu/ focal main' \
    | sudo tee /etc/apt/sources.list.d/kitware.list >/dev/null
sudo apt-get update

sudo rm /usr/share/keyrings/kitware-archive-keyring.gpg
sudo apt-get install kitware-archive-keyring

sudo apt-get install cmake