Juts a side note: Technically, you don't need the mock package. Mock is part of the standard library. Import it from unittest.

I've been missing this as well. This is breaking the certbot package installation :

>[vagrant@centos8 ~]$ sudo yum install certbot
>Last metadata expiration check: 0:00:21 ago on Wed Apr  8 13:02:43 2020.
>Error: 
> Problem: package certbot-1.3.0-3.el8.noarch requires python3-certbot = 1.3.0-3.el8, but none of the providers can be installed
>  - conflicting requests
>  - nothing provides python3-mock needed by python3-certbot-1.3.0-3.el8.noarch
>  - nothing provides python3.6dist(mock) needed by python3-certbot-1.3.0-3.el8.noarch
>(try to add '--skip-broken' to skip uninstallable packages or '--nobest' to use not only best candidate packages)

Repo info :
>[vagrant@centos8 ~]$ cat /etc/yum.repos.d/epel.repo
>[epel]
>name=Extra Packages for Enterprise Linux $releasever - $basearch
>#baseurl=https://download.fedoraproject.org/pub/epel/$releasever/Everything/$basearch
>metalink=https://mirrors.fedoraproject.org/metalink?repo=epel-$releasever&arch=$basearch&infra=$infra&content=$contentdir
>failovermethod=priority
>enabled=1
>gpgcheck=1
>gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL-$releasever

Requiring package :
>[vagrant@centos8 ~]$ yum info python3-certbot
>Last metadata expiration check: 0:00:21 ago on Wed Apr  8 13:02:43 2020.
>Available Packages
>Name         : python3-certbot
>Version      : 1.3.0
>Release      : 3.el8
>Architecture : noarch
>Size         : 367 k
>Source       : certbot-1.3.0-3.el8.src.rpm
>Repository   : epel
>Summary      : Python 3 libraries used by certbot
>URL          : https://pypi.python.org/pypi/certbot
>License      : ASL 2.0
>Description  : The python3 libraries to interface with certbot

If you really need it, it's available over here: https://centos.pkgs.org/8/centos-powertools-x86_64/python3-mock-2.0.0-11.el8.noarch.rpm.html

RPM: http://mirror.centos.org/centos/8/PowerTools/x86_64/os/Packages/python3-mock-2.0.0-11.el8.noarch.rpm
Package provides python3-mock and python3.6dist(mock)

(In reply to j.aukes from comment #3)
> If you really need it, it's available over here:
> https://centos.pkgs.org/8/centos-powertools-x86_64/python3-mock-2.0.0-11.el8.
> noarch.rpm.html
> 
> RPM:
> http://mirror.centos.org/centos/8/PowerTools/x86_64/os/Packages/python3-mock-
> 2.0.0-11.el8.noarch.rpm
> Package provides python3-mock and python3.6dist(mock)

Also seems to be present in Red Hat CodeReady Linux Builder (https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/8/html/package_manifest/codereadylinuxbuilder-repository)

Pierre-Etienne Deutsch: please see https://bugzilla.redhat.com/show_bug.cgi?id=1822959#c1 for further information about the certbot situation. I'm sorry for the incovenience but despite some efforts all attempts to remove the runtime dependency on mock were really complicated and not 100% correct. With a bit of luck the problem will be fixed in certbot 1.4.

Thank you guys !

*** Bug 1815827 has been marked as a duplicate of this bug. ***

Since this is in RHEL 8, it cannot be packaged in EPEL 8.