CMake 3.20 in Ubuntu 18.04 (reversible way)

CMake_3_20_Ubuntu_18_04.md

Motivatation

• modern CMake is required for building a lot of new software
• CMake is dependency for many packages (e.g. ROS related)
• we don't want to remove CMake (which would remove packages that depend on it)
• we want safe procedure to update CMake that can be reversed easily

Current version in OS

Check current version

apt-cache policy cmake

Build CMake 3.20

# get and build CMake
wget https://github.com/Kitware/CMake/releases/download/v3.20.0/cmake-3.20.0.tar.gz
tar -zvxf cmake-3.20.0.tar.gz
cd cmake-3.20.0
./bootstrap
make -j8

Install as package

So that we can easily remove it later

sudo apt-get install checkinstall
# this will take more time than you expect
sudo checkinstall --pkgname=cmake --pkgversion="3.20-custom" --default
# reset shell cache for tools paths
hash -r

Verify installation

apt-cache policy cmake

cmake --version

which cmake

Uninstall

This step only if you want to revert back

• we don't want to remove cmake
• this could cause removal of packages that depend on it (e.g. ROS)
• instead we switch back to previous version

# idenitfy version of interest
apt-cache policy cmake
# switch to different version (from policy above)
apt-get install cmake=VERSION

Thank you.

Anyone on a fresh Ubuntu 18.04 desktop 'minimal' install will need to apt install g++ and libssl-dev first.