$ git clone -n https://src.fedoraproject.org/rpms/luminance-hdr.git /var/lib/mock/f45-build-17728-503/root/chroot_tmpdir/scmroot/luminance-hdr
Cloning into '/var/lib/mock/f45-build-17728-503/root/chroot_tmpdir/scmroot/luminance-hdr'...
$ git fetch origin cfbbf3d0974bb8b5b33234317c6533497e2d3d2e:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/luminance-hdr
 * [new ref]         cfbbf3d0974bb8b5b33234317c6533497e2d3d2e -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at cfbbf3d Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild