$ git clone -n https://src.fedoraproject.org/rpms/R-winch.git /var/lib/mock/f38-build-724049-99309/root/chroot_tmpdir/scmroot/R-winch
Cloning into '/var/lib/mock/f38-build-724049-99309/root/chroot_tmpdir/scmroot/R-winch'...
$ git fetch origin de2aa4bbc724faa26b661211d0f88bb2e9cf9fd6:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-winch
 * [new ref]         de2aa4bbc724faa26b661211d0f88bb2e9cf9fd6 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at de2aa4b update to 0.1.0