Description of problem:
with the recent changes of dnf taking over /usr/bin/yum rpm-ostree is broken

INFO: mock.py version 1.2.7 starting (python version = 3.4.2)...
Start: init plugins
INFO: selinux enabled
Finish: init plugins
Start: run
Start: chroot init
INFO: calling preinit hooks
INFO: enabled yum cache
Start: cleaning yum metadata
Finish: cleaning yum metadata   
INFO: enabled ccache
Finish: chroot init
Start: shell
Previous commit: 3446fb1ee17d2861b6c128bbddbdbd28efa90648da40b63c0bff78224d1264fb
Starting  'yum' '-y' '--disablerepo=*' '--setopt=reposdir=/srv/pungi/fedora-atomic' '--enablerepo=fedora-22' '--enablerepo=fedora-22-bleed' '--setopt=keepcache=0' '--setopt=cachedir=/var/tmp/rpm-ostree.4KAXWX/yum-cache' '--setopt=override_install_langs=e
n_US' '--setopt=tsflags=nodocs' '--installroot=/var/tmp/rpm-ostree.4KAXWX/rootfs.tmp' 'shell'
yum> install atomic
yum> install glibc
yum> install nss-altfiles
yum> install shadow-utils
yum> install fedora-release
yum> install dracut-config-generic
yum> install kernel
yum> install dracut-network
yum> install rpm-ostree
yum> install lvm2
yum> install authconfig
yum> install btrfs-progs
yum> install e2fsprogs
yum> install xfsprogs
yum> install grub2
yum> install grub2-efi
yum> install ostree-grub2
yum> install efibootmgr
yum> install shim
yum> install gnupg2
yum> install basesystem
yum> install bash
yum> install xz
yum> install gzip
yum> install bzip2
yum> install coreutils
yum> install which
yum> install nfs-utils
yum> install curl
yum> install NetworkManager
yum> install hostname
yum> install initscripts
yum> install iproute
yum> install iputils
Yum command has been deprecated, use dnf instead.
See 'man dnf' and 'man yum2dnf' for more information.
To transfer transaction metadata from yum to DNF, run 'dnf migrate'Redirecting to '/usr/bin/dnf -y --disablerepo=* --setopt=reposdir=/srv/pungi/fedora-atomic --enablerepo=fedora-22 --enablerepo=fedora-22-bleed --setopt=keepcache=0 --setopt=cachedir=/var/tmp/rpm-ostree.4KAXWX/yum-cache --setopt=override_install_langs=en_US --setopt=tsflags=nodocs --installroot=/var/tmp/rpm-ostree.4KAXWX/rootfs.tmp shell'

yum> install less
yum> install sos
yum> install openssh-clients
yum> install openssh-server
yum> install passwd
yum> install plymouth
yum> install policycoreutils
yum> install procps-ng
yum> install rootfiles
yum> install rpm
yum> install selinux-policy-targeted
yum> install setup
yum> install shadow-utils
yum> install sudo
yum> install systemd
yum> install util-linux
yum> install vim-minimal
yum> install less
yum> install tar
yum> install cloud-init
yum> install cloud-utils-growpart
yum> install docker-storage-setup
yum> install rsync
yum> install bash-completion
yum> install tmux
yum> install strace
yum> install lsof
yum> install tcpdump
yum> install nmap-ncat
yum> install policycoreutils-python
yum> install setools-console
yum> install audit
yum> install cockpit-bridge
yum> install cockpit-shell
yum> install cockpit-docker
yum> install cockpit-daemon
yum> install kubernetes
yum> install etcd
yum> install flannel
yum> install docker
yum> install python-docker-py
yum> run
Waiting for yum...
Config error: releasever not given and can not be detected from the installroot.
error: Child process exited with code 1
Finish: shell


Marking as an accepted blocker because we can not compose a release blocking component for Beta