$ git clone -n https://src.fedoraproject.org/rpms/R-highr.git /var/lib/mock/f45-build-6283-347/root/chroot_tmpdir/scmroot/R-highr
Cloning into '/var/lib/mock/f45-build-6283-347/root/chroot_tmpdir/scmroot/R-highr'...
$ git fetch origin 1c9026bdef88751e323738c3721bd361076cf1ec:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-highr
 * [new ref]         1c9026bdef88751e323738c3721bd361076cf1ec -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 1c9026b Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild