$ git clone -n https://src.fedoraproject.org/rpms/luminance-hdr.git /var/lib/mock/f42-build-3401480-45130/root/chroot_tmpdir/scmroot/luminance-hdr
Cloning into '/var/lib/mock/f42-build-3401480-45130/root/chroot_tmpdir/scmroot/luminance-hdr'...
$ git fetch origin 0ffc1133d860fe63493fb4c96659e51b547b08d8:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/luminance-hdr
 * [new ref]         0ffc1133d860fe63493fb4c96659e51b547b08d8 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 0ffc113 Patch (preemptively) for Boost>=1.85.0