Thank you sir.
Yesterday night, I followed instructions from these two sites:
Firstly, I installed miniconda and activated automatically initialization
of conda using this site:
https://deeplearning.lipingyang.org/2018/12/24/install-miniconda-on-centos-7-redhat-7/
.
Then, I installed sage using
That's normal. In Sage we only maintain one list of packages for the whole
family of distributions (CentOS, CentOS stream, RHEL, Fedora).
Only the newest versions of Fedora have all the packages.
However, likely on your system you will not be able to build Sage.
We test centos-7 only on a