This post https://www.systutorials.com/1661/making-dnf-yum-not-update-certain-packages/ introduces how to exclude a package from yum.
But is it possible to exclude a package from a specific repository only?
For example, a repository R1 I am using contains an updated version of gdb while I don’t want to use the gdb from it as I trust the version (although older) from the official OS repository. How to make yum update not update gdb from the repository R1?
Mar 29, 2018 at 4:47 pm 
superuser
superuserexclude=... can also be used in each repository’s .repo file under /etc/yum.repos.d.
For the above example, you can add
exclude=gdb
to
/etc/yum.repos.d/R1.repo
under the enabled (enabled=1) sections.
Example:
[epel] name=Extra Packages for Enterprise Linux 7 - $basearch metalink=https://mirrors.fedoraproject.org/metalink?repo=epel-7&arch=$basearch failovermethod=priority enabled=1 gpgcheck=1 gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL-7 exclude=gdb
Mar 29, 2018 at 8:09 pm Eric Ma
Eric Ma