/usr/include/oscpack/ is in liboscpack-dev 1.1.0-2.
This file is owned by root:root, with mode 0o755.
..
/usr/include/oscpack/ip/
/usr/include/oscpack/ip/IpEndpointName.h
/usr/include/oscpack/ip/NetworkingUtils.h
/usr/include/oscpack/ip/PacketListener.h
/usr/include/oscpack/ip/TimerListener.h
/usr/include/oscpack/ip/UdpSocket.h
/usr/include/oscpack/osc/
/usr/include/oscpack/osc/MessageMappingOscPacketListener.h
/usr/include/oscpack/osc/OscException.h
/usr/include/oscpack/osc/OscHostEndianness.h
/usr/include/oscpack/osc/OscOutboundPacketStream.h
/usr/include/oscpack/osc/OscPacketListener.h
/usr/include/oscpack/osc/OscPrintReceivedElements.h
/usr/include/oscpack/osc/OscReceivedElements.h
/usr/include/oscpack/osc/OscTypes.h