$ git clone -n https://src.fedoraproject.org/rpms/repo.git /var/lib/mock/f45-build-34463-687/root/chroot_tmpdir/scmroot/repo
Cloning into '/var/lib/mock/f45-build-34463-687/root/chroot_tmpdir/scmroot/repo'...
$ git fetch origin 861b2dab98c050e7fcb124bdbeb27f04cba25576:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/repo
 * [new ref]         861b2dab98c050e7fcb124bdbeb27f04cba25576 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 861b2da Update to 2.67