$ git clone -n https://src.fedoraproject.org/rpms/gstreamermm.git /var/lib/mock/f39-build-1823818-41848/root/chroot_tmpdir/scmroot/gstreamermm
Cloning into '/var/lib/mock/f39-build-1823818-41848/root/chroot_tmpdir/scmroot/gstreamermm'...
$ git fetch origin dd209a0e43d001ccab6cd4504644236dd15a8cef:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gstreamermm
 * [new ref]         dd209a0e43d001ccab6cd4504644236dd15a8cef -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at dd209a0 Rebuilt for https://fedoraproject.org/wiki/Fedora_39_Mass_Rebuild