Для RockyLinux 8 запустите от имени root:
cd /etc/yum.repos.d/
wget https://download.opensuse.org/repositories/home:nio-infra:3rdparty/RockyLinux_8/home:nio-infra:3rdparty.repo
yum install python-aniso8601
Для CentOS 8 запустите от имени root:
cd /etc/yum.repos.d/
wget https://download.opensuse.org/repositories/home:nio-infra:3rdparty/CentOS_8/home:nio-infra:3rdparty.repo
yum install python-aniso8601
Для CentOS 7 запустите от имени root:
cd /etc/yum.repos.d/
wget https://download.opensuse.org/repositories/home:nio-infra:3rdparty/CentOS_7/home:nio-infra:3rdparty.repo
yum install python-aniso8601