$ git clone -n https://src.fedoraproject.org/rpms/binutils.git /var/lib/mock/f42-build-867400-175487/root/chroot_tmpdir/scmroot/binutils
Cloning into '/var/lib/mock/f42-build-867400-175487/root/chroot_tmpdir/scmroot/binutils'...
$ git fetch origin 6cb8c76a06af7ce9b3fa3eaeafb9fe310f5913d0:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/binutils
 * [new ref]         6cb8c76a06af7ce9b3fa3eaeafb9fe310f5913d0 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 6cb8c76 Rebase to commit f832531609d