I’m trying to install cmake on my ubuntu 20.04 VM. I tried to install cmake manually by downloading the tar, and running through the installation. However, when i use apt-cache policy cmake, my machine says I don’t have cmake installed. However, I can use cmake. The second problem I have is that I can’t use ctest, even though I would expect it to work. If I use sudo apt install cmake, 3.16.3-1ubuntu1 is installed. Is there a difference between CMake 3.16.3-1ubuntu1 and CMake 3.20.0-rc3?
Unpacking a tarball is not “installing” as far as apt is concerned, so it won’t care or know what you’ve done.
What problem do you have running ctest?
Yes. Ubuntu packages an older version as of right now. CMake development works on a different cycle. We do provide apt repositories at https://apt.kitware.com if you would like to use apt to install the latest pre-releases.