Adding Repo by yum-config-manager

[arielvns]

Hi,
I will trying to add docker-ce repo with yum and have an error with yum-config-manager file.

I launchs with:
sudo yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo
yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo

This fails with:

Traceback (most recent call last):
File "/usr/bin/yum-config-manager", line 202, in
grabber = yb.repos.listEnabled()[0].grabfunc
IndexError: list index out of range

Thanks in advance,
Ariel.