$ git clone -n https://src.fedoraproject.org/rpms/R-waldo.git /var/lib/mock/f43-build-side-110352-58922563-6569272/root/chroot_tmpdir/scmroot/R-waldo
Cloning into '/var/lib/mock/f43-build-side-110352-58922563-6569272/root/chroot_tmpdir/scmroot/R-waldo'...
$ git fetch origin 12e3ea899e1901bc2f9d3a7b1e2b7336bcf3e850:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-waldo
 * [new ref]         12e3ea899e1901bc2f9d3a7b1e2b7336bcf3e850 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 12e3ea8 Update to latest version