$ git clone -n https://src.fedoraproject.org/rpms/kea.git /var/lib/mock/f45-build-14744-463/root/chroot_tmpdir/scmroot/kea
Cloning into '/var/lib/mock/f45-build-14744-463/root/chroot_tmpdir/scmroot/kea'...
$ git fetch origin db7990d7d6bf308736d40efcfeee06a53a81615d:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/kea
 * [new ref]         db7990d7d6bf308736d40efcfeee06a53a81615d -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at db7990d Run scriptlet in %pre instead of %pretrans