$ git clone -n https://src.fedoraproject.org/rpms/R-tweenr.git /var/lib/mock/f38-build-724371-99434/root/chroot_tmpdir/scmroot/R-tweenr
Cloning into '/var/lib/mock/f38-build-724371-99434/root/chroot_tmpdir/scmroot/R-tweenr'...
$ git fetch origin 392ffb2685b50837563d7fd738f37d5c81ae3633:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-tweenr
 * [new ref]         392ffb2685b50837563d7fd738f37d5c81ae3633 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 392ffb2 R-maint-sig mass rebuild