failed to build the cmake_pcl example

[jingnanshi]

Hi,

Thank you for your awesome project. I was trying to build the cmake_pcl example, but I encountered some errors with respect to flann. The following is the segment showing the error:

-- The C compiler identification is GNU 7.4.0
-- The CXX compiler identification is GNU 7.4.0
-- Check for working C compiler: /usr/bin/gcc
-- Check for working C compiler: /usr/bin/gcc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Detecting C compile features
-- Detecting C compile features - done
-- Check for working CXX compiler: /usr/bin/gcc
-- Check for working CXX compiler: /usr/bin/gcc -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Found PythonInterp: /usr/bin/python (found version "2.7.15") 
-- HDF5: Using hdf5 compiler wrapper to determine C configuration
-- Found HDF5: /usr/lib/x86_64-linux-gnu/hdf5/serial/libhdf5.so;/usr/lib/x86_64-linux-gnu/libpthread.so;/usr/lib/x86_64-linux-gnu/libsz.so;/usr/lib/x86_64-linux-gnu/libz.so;/usr/lib/x86_64-linux-gnu/libdl.so;/usr/lib/x86_64-linux-gnu/libm.so (found version "1.10.0.1")  
-- Could NOT find GTest (missing: GTEST_LIBRARY GTEST_INCLUDE_DIR GTEST_MAIN_LIBRARY) 
CMake Warning at CMakeLists.txt:117 (message):
  gtest library not found, some tests will not be run


-- Found OpenMP_C: -fopenmp (found version "4.5") 
-- Found OpenMP_CXX: -fopenmp (found version "4.5") 
-- Found OpenMP: TRUE (found version "4.5")  
CMake Warning (dev) at src/matlab/CMakeLists.txt:19 (get_property):
  Policy CMP0026 is not set: Disallow use of the LOCATION target property.
  Run "cmake --help-policy CMP0026" for policy details.  Use the cmake_policy
  command to set the policy and suppress this warning.

  The LOCATION property should not be read from target "flann_s".  Use the
  target name directly with add_custom_command, or use the generator
  expression $<TARGET_FILE>, as appropriate.

This warning is for project developers.  Use -Wno-dev to suppress it.

-- Found MATLAB at: /usr/local/MATLAB/R2019a/bin
-- Found LATEX: /usr/bin/latex   
-- I could not find the latex2html command.
-- Install prefix: /tmp/tmp.08dKXuwifU/flann
-- Build type: Release
-- Building C bindings: ON
-- Building examples: ON
-- Building tests: ON
-- Building documentation: ON
-- Building python bindings: ON
-- Building matlab bindings: ON
-- Building CUDA library: OFF
-- Using OpenMP support: ON
-- Using MPI support: OFF
-- Configuring done
CMake Error at src/cpp/CMakeLists.txt:32 (add_library):
  No SOURCES given to target: flann_cpp


CMake Error at src/cpp/CMakeLists.txt:86 (add_library):
  No SOURCES given to target: flann


CMake Generate step failed.  Build files cannot be regenerated correctly.

Any help will be appreciated. Thank you.

[jingnanshi]

It turned out that this is a issue with the CMakeList of the flann package. See this. When I changed CMake to 3.10, things start to work again.