报错：
Using PYTHON_EXECUTABLE: /home/tjsiasun/miniconda3/envs/pointpillar2/bin/python3
-- Using Debian Python package layout
-- Could NOT find PY_em (missing: PY_EM)
CMake Error at /opt/ros/noetic/share/catkin/cmake/empy.cmake:30 (message):
Unable to find either executable 'empy' or Python module 'em'... try
installing the package 'python3-empy'
Call Stack (most recent call first):
/opt/ros/noetic/share/catkin/cmake/all.cmake:164 (include)
/opt/ros/noetic/share/catkin/cmake/catkinConfig.cmake:20 (include)
CMakeLists.txt:58 (find_package)
解决：
编译时指定python环境
catkin_make -DPYTHON_EXECUTABLE=/usr/bin/python3