CMake error caused by the merge of #2100

[jasjuang]

Your Environment

• Operating System and version: Ubuntu 18.04
• Compiler: GCC 7
• PCL Version: Latest

Context

With the latest merge of #2100, there is a problem when a library is linking to another library that links to PCL, please see below minimal to reproduce the problem.

CMakeLists.txt

cmake_minimum_required(VERSION 3.11)

project(sample)

find_package( PCL REQUIRED )

add_library(${PROJECT_NAME} SHARED Sample.cpp Sample.h)

target_link_libraries(${PROJECT_NAME} ${PCL_LIBRARIES})

add_subdirectory(sample2)

Sample.cpp

#include "Sample.h"

Sample::Sample() {}

Sample::~Sample() {}

Sample.h

class Sample{
 public:
  Sample();
  ~Sample();
};

sample2/CMakeLists.txt

cmake_minimum_required(VERSION 3.11)

project(sample2)

find_package( PCL REQUIRED )

add_library(${PROJECT_NAME} SHARED Sample2.cpp Sample2.h)

# not even linking to ${PCL_LIBRARIES}
target_link_libraries(${PROJECT_NAME} sample)

sample2/Sample2.cpp

#include "Sample2.h"

Sample2::Sample2() {}

Sample2::~Sample2() {}

sample2/Sample2.h

class Sample2{
 public:
  Sample2();
  ~Sample2();
};

Expected Behavior

After

mkdir build 
cd build 
cmake ..

It should work without a problem.

Current Behavior

However, here is the output

-- Eigen found (include: /usr/include/eigen3, version: 3.3.90)
-- Boost version: 1.65.1
-- Found the following Boost libraries:
--   system
--   filesystem
--   thread
--   date_time
--   iostreams
--   serialization
--   chrono
--   atomic
--   regex
-- FLANN found (include: /usr/include, lib: optimized;/usr/lib/libflann_cpp.so;debug;/usr/lib/libflann_cpp.so)
-- FLANN found (include: /usr/include, lib: optimized;/usr/lib/libflann_cpp.so;debug;/usr/lib/libflann_cpp.so)
** WARNING ** io features related to pcap will be disabled
** WARNING ** io features related to png will be disabled
-- LIBUSB_1_LIBRARY (missing: LIBUSB_1_INCLUDE_DIR) 
** WARNING ** io features related to libusb-1.0 will be disabled
-- QHULL found (include: /usr/include, lib: optimized;/usr/lib/x86_64-linux-gnu/libqhull.so;debug;/usr/lib/x86_64-linux-gnu/libqhull.so)
-- looking for PCL_COMMON
-- looking for PCL_KDTREE
-- looking for PCL_OCTREE
-- looking for PCL_SEARCH
-- looking for PCL_SAMPLE_CONSENSUS
-- looking for PCL_FILTERS
-- looking for PCL_2D
-- looking for PCL_GEOMETRY
-- looking for PCL_IO
-- looking for PCL_FEATURES
-- looking for PCL_ML
-- looking for PCL_SEGMENTATION
-- looking for PCL_VISUALIZATION
-- looking for PCL_SURFACE
-- looking for PCL_REGISTRATION
-- looking for PCL_KEYPOINTS
-- looking for PCL_TRACKING
-- looking for PCL_RECOGNITION
-- looking for PCL_STEREO
-- looking for PCL_CUDA_COMMON
-- looking for PCL_CUDA_FEATURES
-- looking for PCL_CUDA_SEGMENTATION
-- looking for PCL_CUDA_SAMPLE_CONSENSUS
-- looking for PCL_OUTOFCORE
-- looking for PCL_GPU_CONTAINERS
-- looking for PCL_GPU_UTILS
-- looking for PCL_GPU_OCTREE
-- looking for PCL_GPU_FEATURES
-- looking for PCL_GPU_SEGMENTATION
-- looking for PCL_PEOPLE
-- Eigen found (include: /usr/include/eigen3, version: 3.3.90)
-- Boost version: 1.65.1
-- Found the following Boost libraries:
--   system
--   filesystem
--   thread
--   date_time
--   iostreams
--   serialization
--   chrono
--   atomic
--   regex
-- FLANN found (include: /usr/include, lib: optimized;/usr/lib/libflann_cpp.so;debug;/usr/lib/libflann_cpp.so)
-- FLANN found (include: /usr/include, lib: optimized;/usr/lib/libflann_cpp.so;debug;/usr/lib/libflann_cpp.so)
** WARNING ** io features related to pcap will be disabled
** WARNING ** io features related to png will be disabled
-- LIBUSB_1_LIBRARY (missing: LIBUSB_1_INCLUDE_DIR) 
** WARNING ** io features related to libusb-1.0 will be disabled
-- QHULL found (include: /usr/include, lib: optimized;/usr/lib/x86_64-linux-gnu/libqhull.so;debug;/usr/lib/x86_64-linux-gnu/libqhull.so)
-- looking for PCL_COMMON
CMake Error at /usr/share/pcl-1.8/PCLConfig.cmake:630 (add_library):
  add_library cannot create imported target "pcl_common" because another
  target with the same name already exists.
Call Stack (most recent call first):
  sample2/CMakeLists.txt:5 (find_package)


-- looking for PCL_KDTREE
CMake Error at /usr/share/pcl-1.8/PCLConfig.cmake:630 (add_library):
  add_library cannot create imported target "pcl_kdtree" because another
  target with the same name already exists.
Call Stack (most recent call first):
  sample2/CMakeLists.txt:5 (find_package)


-- looking for PCL_OCTREE
CMake Error at /usr/share/pcl-1.8/PCLConfig.cmake:630 (add_library):
  add_library cannot create imported target "pcl_octree" because another
  target with the same name already exists.
Call Stack (most recent call first):
  sample2/CMakeLists.txt:5 (find_package)


-- looking for PCL_SEARCH
CMake Error at /usr/share/pcl-1.8/PCLConfig.cmake:630 (add_library):
  add_library cannot create imported target "pcl_search" because another
  target with the same name already exists.
Call Stack (most recent call first):
  sample2/CMakeLists.txt:5 (find_package)


-- looking for PCL_SAMPLE_CONSENSUS
CMake Error at /usr/share/pcl-1.8/PCLConfig.cmake:630 (add_library):
  add_library cannot create imported target "pcl_sample_consensus" because
  another target with the same name already exists.
Call Stack (most recent call first):
  sample2/CMakeLists.txt:5 (find_package)


-- looking for PCL_FILTERS
CMake Error at /usr/share/pcl-1.8/PCLConfig.cmake:630 (add_library):
  add_library cannot create imported target "pcl_filters" because another
  target with the same name already exists.
Call Stack (most recent call first):
  sample2/CMakeLists.txt:5 (find_package)


-- looking for PCL_2D
-- looking for PCL_GEOMETRY
-- looking for PCL_IO
CMake Error at /usr/share/pcl-1.8/PCLConfig.cmake:630 (add_library):
  add_library cannot create imported target "pcl_io" because another target
  with the same name already exists.
Call Stack (most recent call first):
  sample2/CMakeLists.txt:5 (find_package)


-- looking for PCL_FEATURES
CMake Error at /usr/share/pcl-1.8/PCLConfig.cmake:630 (add_library):
  add_library cannot create imported target "pcl_features" because another
  target with the same name already exists.
Call Stack (most recent call first):
  sample2/CMakeLists.txt:5 (find_package)


-- looking for PCL_ML
CMake Error at /usr/share/pcl-1.8/PCLConfig.cmake:630 (add_library):
  add_library cannot create imported target "pcl_ml" because another target
  with the same name already exists.
Call Stack (most recent call first):
  sample2/CMakeLists.txt:5 (find_package)


-- looking for PCL_SEGMENTATION
CMake Error at /usr/share/pcl-1.8/PCLConfig.cmake:630 (add_library):
  add_library cannot create imported target "pcl_segmentation" because
  another target with the same name already exists.
Call Stack (most recent call first):
  sample2/CMakeLists.txt:5 (find_package)


-- looking for PCL_VISUALIZATION
CMake Error at /usr/share/pcl-1.8/PCLConfig.cmake:630 (add_library):
  add_library cannot create imported target "pcl_visualization" because
  another target with the same name already exists.
Call Stack (most recent call first):
  sample2/CMakeLists.txt:5 (find_package)


-- looking for PCL_SURFACE
CMake Error at /usr/share/pcl-1.8/PCLConfig.cmake:630 (add_library):
  add_library cannot create imported target "pcl_surface" because another
  target with the same name already exists.
Call Stack (most recent call first):
  sample2/CMakeLists.txt:5 (find_package)


-- looking for PCL_REGISTRATION
CMake Error at /usr/share/pcl-1.8/PCLConfig.cmake:630 (add_library):
  add_library cannot create imported target "pcl_registration" because
  another target with the same name already exists.
Call Stack (most recent call first):
  sample2/CMakeLists.txt:5 (find_package)


-- looking for PCL_KEYPOINTS
CMake Error at /usr/share/pcl-1.8/PCLConfig.cmake:630 (add_library):
  add_library cannot create imported target "pcl_keypoints" because another
  target with the same name already exists.
Call Stack (most recent call first):
  sample2/CMakeLists.txt:5 (find_package)


-- looking for PCL_TRACKING
CMake Error at /usr/share/pcl-1.8/PCLConfig.cmake:630 (add_library):
  add_library cannot create imported target "pcl_tracking" because another
  target with the same name already exists.
Call Stack (most recent call first):
  sample2/CMakeLists.txt:5 (find_package)


-- looking for PCL_RECOGNITION
CMake Error at /usr/share/pcl-1.8/PCLConfig.cmake:630 (add_library):
  add_library cannot create imported target "pcl_recognition" because another
  target with the same name already exists.
Call Stack (most recent call first):
  sample2/CMakeLists.txt:5 (find_package)


-- looking for PCL_STEREO
CMake Error at /usr/share/pcl-1.8/PCLConfig.cmake:630 (add_library):
  add_library cannot create imported target "pcl_stereo" because another
  target with the same name already exists.
Call Stack (most recent call first):
  sample2/CMakeLists.txt:5 (find_package)


-- looking for PCL_CUDA_COMMON
-- looking for PCL_CUDA_FEATURES
CMake Error at /usr/share/pcl-1.8/PCLConfig.cmake:630 (add_library):
  add_library cannot create imported target "pcl_cuda_features" because
  another target with the same name already exists.
Call Stack (most recent call first):
  sample2/CMakeLists.txt:5 (find_package)


-- looking for PCL_CUDA_SEGMENTATION
CMake Error at /usr/share/pcl-1.8/PCLConfig.cmake:630 (add_library):
  add_library cannot create imported target "pcl_cuda_segmentation" because
  another target with the same name already exists.
Call Stack (most recent call first):
  sample2/CMakeLists.txt:5 (find_package)


-- looking for PCL_CUDA_SAMPLE_CONSENSUS
CMake Error at /usr/share/pcl-1.8/PCLConfig.cmake:630 (add_library):
  add_library cannot create imported target "pcl_cuda_sample_consensus"
  because another target with the same name already exists.
Call Stack (most recent call first):
  sample2/CMakeLists.txt:5 (find_package)


-- looking for PCL_OUTOFCORE
CMake Error at /usr/share/pcl-1.8/PCLConfig.cmake:630 (add_library):
  add_library cannot create imported target "pcl_outofcore" because another
  target with the same name already exists.
Call Stack (most recent call first):
  sample2/CMakeLists.txt:5 (find_package)


-- looking for PCL_GPU_CONTAINERS
CMake Error at /usr/share/pcl-1.8/PCLConfig.cmake:630 (add_library):
  add_library cannot create imported target "pcl_gpu_containers" because
  another target with the same name already exists.
Call Stack (most recent call first):
  sample2/CMakeLists.txt:5 (find_package)


-- looking for PCL_GPU_UTILS
CMake Error at /usr/share/pcl-1.8/PCLConfig.cmake:630 (add_library):
  add_library cannot create imported target "pcl_gpu_utils" because another
  target with the same name already exists.
Call Stack (most recent call first):
  sample2/CMakeLists.txt:5 (find_package)


-- looking for PCL_GPU_OCTREE
CMake Error at /usr/share/pcl-1.8/PCLConfig.cmake:630 (add_library):
  add_library cannot create imported target "pcl_gpu_octree" because another
  target with the same name already exists.
Call Stack (most recent call first):
  sample2/CMakeLists.txt:5 (find_package)


-- looking for PCL_GPU_FEATURES
CMake Error at /usr/share/pcl-1.8/PCLConfig.cmake:630 (add_library):
  add_library cannot create imported target "pcl_gpu_features" because
  another target with the same name already exists.
Call Stack (most recent call first):
  sample2/CMakeLists.txt:5 (find_package)


-- looking for PCL_GPU_SEGMENTATION
CMake Error at /usr/share/pcl-1.8/PCLConfig.cmake:630 (add_library):
  add_library cannot create imported target "pcl_gpu_segmentation" because
  another target with the same name already exists.
Call Stack (most recent call first):
  sample2/CMakeLists.txt:5 (find_package)


-- looking for PCL_PEOPLE
CMake Error at /usr/share/pcl-1.8/PCLConfig.cmake:630 (add_library):
  add_library cannot create imported target "pcl_people" because another
  target with the same name already exists.
Call Stack (most recent call first):
  sample2/CMakeLists.txt:5 (find_package)

-- Configuring incomplete, errors occurred!

This problem pops up only after the merge of #2100, if I remove the find_package( PCL REQUIRED ) in sample2/CMakeLists.txt the error goes away, but I should be allowed to call find_package( PCL REQUIRED ) in sample2/CMakeLists.txt even if it's redundant.

[taketwo]

Could you please post this as a gist or small repo so I can directly check out all the files? I'll have a look.

[jasjuang]

@taketwo Please see https://gist.github.com/jasjuang/8744547bf3e0c43b8d89ca5999a7c4f2

[taketwo]

Thanks. See #2428.