conflicting declaration ‘typedef struct LZ4_stream_t LZ4_stream_t’解决

问题参考及解决：https://github.com/ethz-asl/lidar_align/issues/16
终端输入：

sudo mv /usr/include/flann/ext/lz4.h /usr/include/flann/ext/lz4.h.bak
sudo mv /usr/include/flann/ext/lz4hc.h /usr/include/flann/ext/lz4.h.bak

sudo ln -s /usr/include/lz4.h /usr/include/flann/ext/lz4.h
sudo ln -s /usr/include/lz4hc.h /usr/include/flann/ext/lz4hc.h

REF：https://www.cnblogs.com/long5683/p/13596814.html