dnf.conf gets reset every time the chroot gets entered.
# install rhpkg
$MOCK -i ~martin/Dokumente/Arbeit/RedHat/redhat-internal-cert-install-0.1-7.el7.csb.noarch.rpm
-$MOCK --chroot --cwd=/etc/yum.repos.d -- 'echo >> /etc/dnf/dnf.conf; curl --location https://download.devel.redhat.com/rel-eng/RCMTOOLS/rcm-tools-fedora.repo >> /etc/dnf/dnf.conf'
-$MOCK -i rhpkg
+$MOCK --chroot -- 'echo >> /etc/dnf/dnf.conf; curl --location https://download.devel.redhat.com/rel-eng/RCMTOOLS/rcm-tools-fedora.repo >> /etc/dnf/dnf.conf; dnf install -y rhpkg'
# ssh looks at passwd, not $HOME
$MOCK --chroot --unpriv -- rm -rf /builddir/.ssh