Upgrading cmake

Linux build requires cmake 3.12 or newer. Older versions do not have right support for fining Python headers. To upgrade smake, first remove current cmake which came with distribution:

sudo apt-get remove cmake

Install cmake to /usr/local. This is not nice debian package install, but should work.

sudo wget -qO- "https://cmake.org/files/v3.18/cmake-3.18.0-Linux-x86_64.tar.gz" | sudo tar --strip-components=1 -xz -C /usr/local

qtcreator: path to cmake needs to be set in [Tools][Options], “Build and run”, [Cmake] tab: Set”/usr/local/bin/cmake”.