$ git clone -n https://src.fedoraproject.org/rpms/R-mockery.git /var/lib/mock/f45-build-6238-347/root/chroot_tmpdir/scmroot/R-mockery
Cloning into '/var/lib/mock/f45-build-6238-347/root/chroot_tmpdir/scmroot/R-mockery'...
$ git fetch origin 2e3cddceef383e2514a6347324cfda81343edee4:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-mockery
 * [new ref]         2e3cddceef383e2514a6347324cfda81343edee4 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 2e3cddc Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild