Hello all,

It looks as if there are some problems with two different lz4.h files. I'm using gsl 2.4 and pcl 1.8. I'm also running ros on gentoo:

In file included from /opt/ros/kinetic/include/roslz4/lz4s.h:38:0,
                 from /opt/ros/kinetic/include/rosbag/stream.h:46,
                 from /opt/ros/kinetic/include/rosbag/chunked_file.h:46,
                 from /opt/ros/kinetic/include/rosbag/bag.h:41,
                 from /home/malcolm/ros_catkin_ws/kinetic_src/src/perception_oru-private/ndt_offline/include/ndt_offline/PoseInterpolationNavMsgsOdo.h:6,
                 from /home/malcolm/ros_catkin_ws/kinetic_src/src/perception_oru-private/ndt_calibration/include/ndt_calibration/ndt_calib.h:14,
                 from /home/malcolm/ros_catkin_ws/kinetic_src/src/perception_oru-private/ndt_calibration/src/ndt_calib.cpp:1:
/usr/include/lz4.h:234:28: error: conflicting declaration ‘typedef union LZ4_stream_u LZ4_stream_t’
 typedef union LZ4_stream_u LZ4_stream_t;   /* incomplete type (defined later) */
                            ^
In file included from /usr/include/flann/util/serialization.h:9:0,
                 from /usr/include/flann/util/matrix.h:35,
                 from /usr/include/flann/flann.hpp:41,
                 from /usr/include/pcl-1.8/pcl/kdtree/flann.h:50,
                 from /usr/include/pcl-1.8/pcl/kdtree/kdtree_flann.h:45,
                 from /home/malcolm/ros_catkin_ws/kinetic_src/src/perception_oru-private/ndt_calibration/include/ndt_calibration/ndt_calib.h:9,
                 from /home/malcolm/ros_catkin_ws/kinetic_src/src/perception_oru-private/ndt_calibration/src/ndt_calib.cpp:1:
/usr/include/flann/ext/lz4.h:196:57: note: previous declaration as ‘typedef struct LZ4_stream_t LZ4_stream_t’
 typedef struct { long long table[LZ4_STREAMSIZE_U64]; } LZ4_stream_t;

Not sure what to do with this :)