$ git clone -n https://src.fedoraproject.org/rpms/R-tkrplot.git /var/lib/mock/f45-build-6484-348/root/chroot_tmpdir/scmroot/R-tkrplot
Cloning into '/var/lib/mock/f45-build-6484-348/root/chroot_tmpdir/scmroot/R-tkrplot'...
$ git fetch origin d73f48f311f4cdad49b2dfeeeb89a26321b65e98:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-tkrplot
 * [new ref]         d73f48f311f4cdad49b2dfeeeb89a26321b65e98 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at d73f48f Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild