From Christian Noon, "Got a simple patch for correcting a problem with the USE_COMPRESSOR_WRAPPER() macro in the osgDB::Registry. The problem is that the wrapper declaration doesn't match the one defined in the REGISTER_COMPRESSOR() method in the osgDB::ObjectWrapper method. This patch fixes the wrapper declaration so they both match properly. I ran into this problem using compressed files in an iOS application where all the libraries and plugins need to be built statically."