$ git clone -n https://src.fedoraproject.org/rpms/R-poLCA.git /var/lib/mock/f45-build-6321-347/root/chroot_tmpdir/scmroot/R-poLCA
Cloning into '/var/lib/mock/f45-build-6321-347/root/chroot_tmpdir/scmroot/R-poLCA'...
$ git fetch origin 137e31265a79decfb587ff91ee0ef306a1e0800e:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-poLCA
 * [new ref]         137e31265a79decfb587ff91ee0ef306a1e0800e -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 137e312 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild