Patch to fix standard/empty rpaths:
    /usr/lib/rpm/check-rpaths /usr/lib/rpm/check-buildroot ERROR: file
        '/usr/lib/pl-5.4.6/xpce-6.4.3/lib/i686-linux-gnu/pl2xpce.so' contains a
        standard rpath '/usr/lib' in [/usr/lib:] ERROR: file
        '/usr/lib/pl-5.4.6/xpce-6.4.3/lib/i686-linux-gnu/pl2xpce.so' contains
        an empty rpath in [/usr/lib:]