$ git clone -n https://src.fedoraproject.org/rpms/R-pillar.git /var/lib/mock/f45-build-6297-347/root/chroot_tmpdir/scmroot/R-pillar
Cloning into '/var/lib/mock/f45-build-6297-347/root/chroot_tmpdir/scmroot/R-pillar'...
$ git fetch origin 96894323a4d8a6e66ab474c4f9dc7c5aa0ccf011:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-pillar
 * [new ref]         96894323a4d8a6e66ab474c4f9dc7c5aa0ccf011 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 9689432 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild