$ git clone -n https://src.fedoraproject.org/rpms/coreutils.git /var/lib/mock/f42-build-side-1-3562226-46722/root/chroot_tmpdir/scmroot/coreutils
Cloning into '/var/lib/mock/f42-build-side-1-3562226-46722/root/chroot_tmpdir/scmroot/coreutils'...
$ git fetch origin 808a3165673f80423f6576b734c91ea50a8ca8c0:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/coreutils
 * [new ref]         808a3165673f80423f6576b734c91ea50a8ca8c0 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 808a316 sort: fix buffer under-read