Could NOT find Threads (missing: Threads_FOUND) on Raspberry 4 and F200

[shoomilka]

Required Info
Camera Model	F200
Firmware Version	-
Operating System & Version	Raspberry Pi OS (bullseye)
Kernel Version (Linux Only)	5.15.32-v8+
Build System	Makefile

I'm installing on Raspberry 400 driver for F200 and doing command cmake .. -DBUILD_EXAMPLES=true -DCMAKE_BUILD_TYPE=Release -DFORCE_LIBUVC=true, I received an error:

-- Info: REALSENSE_VERSION_STRING=1.12.1
CMake Error at /usr/share/cmake-3.18/Modules/FindPackageHandleStandardArgs.cmake:165 (message):
  Could NOT find Threads (missing: Threads_FOUND)
Call Stack (most recent call first):
  /usr/share/cmake-3.18/Modules/FindPackageHandleStandardArgs.cmake:458 (_FPHSA_FAILURE_MESSAGE)
  /usr/share/cmake-3.18/Modules/FindThreads.cmake:234 (FIND_PACKAGE_HANDLE_STANDARD_ARGS)
  CMakeLists.txt:173 (find_package)

Can you help me to fix that?

[congvmit]

Hello @shoomilka
It's been a long time since I started this project. So I am not sure the solution I found can work for you or not.
You can check the solution from this link:
IntelRealSense/librealsense#10041 (comment)

[shoomilka]

Hi, @congvmit ! Thank you for the idea but it didn't help(((( I now saw that the error looks the next: Looking for pthread.h - not found. I checked the locate function for this .h file and it said that there are two files with this name. But I cannot understand why compiler doesn't see it...

[congvmit]

@shoomilka Have you tried this solution?
alicevision/geogram#2 (comment)

I think your problem is quite common. You may find the solutions from other repositories, I believe.

[shoomilka]

@congvmit , now I received an output:

shoomilka@raspberrypi:~/real/librealsense_for_arm/build $ cmake .. -DBUILD_EXAMPLES=true -DCMAKE_BUILD_TYPE=Release -DFORCE_LIBUVC=true
-- Info: REALSENSE_VERSION_STRING=1.12.1
-- The C compiler identification is GNU 10.2.1
-- The CXX compiler identification is GNU 10.2.1
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working C compiler: /usr/bin/cc - skipped
-- Detecting C compile features
-- Detecting C compile features - done
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: /usr/bin/c++ - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Performing Test COMPILER_SUPPORTS_CXX11
-- Performing Test COMPILER_SUPPORTS_CXX11 - Success
-- Performing Test COMPILER_SUPPORTS_CXX0X
-- Performing Test COMPILER_SUPPORTS_CXX0X - Success
-- Found PkgConfig: /usr/bin/pkg-config (found version "0.29.2") 
-- Looking for pthread.h
-- Looking for pthread.h - not found
-- Found Threads: TRUE  
-- Checking for one of the modules 'libusb-1.0'
CMake Warning (dev) at /usr/share/cmake-3.18/Modules/FindOpenGL.cmake:305 (message):
  Policy CMP0072 is not set: FindOpenGL prefers GLVND by default when
  available.  Run "cmake --help-policy CMP0072" for policy details.  Use the
  cmake_policy command to set the policy and suppress this warning.

  FindOpenGL found both a legacy GL library:

    OPENGL_gl_LIBRARY: /usr/lib/aarch64-linux-gnu/libGL.so

  and GLVND libraries for OpenGL and GLX:

    OPENGL_opengl_LIBRARY: /usr/lib/aarch64-linux-gnu/libOpenGL.so
    OPENGL_glx_LIBRARY: /usr/lib/aarch64-linux-gnu/libGLX.so

  OpenGL_GL_PREFERENCE has not been set to "GLVND" or "LEGACY", so for
  compatibility with CMake 3.10 and below the legacy GL library will be used.
Call Stack (most recent call first):
  examples/CMakeLists.txt:24 (find_package)
This warning is for project developers.  Use -Wno-dev to suppress it.

-- Found OpenGL: /usr/lib/aarch64-linux-gnu/libOpenGL.so   
-- Configuring done
-- Generating done
CMake Warning:
  Manually-specified variables were not used by the project:

    FORCE_LIBUVC


-- Build files have been written to: /home/shoomilka/real/librealsense_for_arm/build

I think I can ignore this warning (maybe I'm wrong), so I decided to do the next:

shoomilka@raspberrypi:~/real/librealsense_for_arm/build $ make -j3
Scanning dependencies of target realsense
[  1%] Building CXX object CMakeFiles/realsense.dir/src/context.cpp.o
[  2%] Building CXX object CMakeFiles/realsense.dir/src/device.cpp.o
[  3%] Building CXX object CMakeFiles/realsense.dir/src/archive.cpp.o
c++: error: unrecognized command-line option ‘-mfpu=neon’
c++: error: unrecognized command-line option ‘-mfpu=neon’
c++: error: unrecognized command-line option ‘-mfloat-abi=hard’
c++: error: unrecognized command-line option ‘-mfpu=neon’
make[2]: *** [CMakeFiles/realsense.dir/build.make:95: CMakeFiles/realsense.dir/src/context.cpp.o] Error 1
make[2]: *** Waiting for unfinished jobs....
c++: error: unrecognized command-line option ‘-mfloat-abi=hard’
make[2]: *** [CMakeFiles/realsense.dir/build.make:108: CMakeFiles/realsense.dir/src/device.cpp.o] Error 1
c++: error: unrecognized command-line option ‘-mfloat-abi=hard’
make[2]: *** [CMakeFiles/realsense.dir/build.make:82: CMakeFiles/realsense.dir/src/archive.cpp.o] Error 1
make[1]: *** [CMakeFiles/Makefile2:208: CMakeFiles/realsense.dir/all] Error 2
make: *** [Makefile:149: all] Error 2

Now looking for the solution on this.

Thank you for the last message - it very helped.

[shoomilka]

I think the reason is the net lines of code in CMakeLists.txt:

if(${MACHINE} MATCHES "arm-linux-gnueabihf")
      set(CMAKE_C_FLAGS   "${CMAKE_C_FLAGS}   -mfpu=neon -mfloat-abi=hard -ftree-vectorize")
      set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -mfpu=neon -mfloat-abi=hard -ftree-vectorize")
    elseif(${MACHINE} MATCHES "aarch64-linux-gnu")
      set(CMAKE_C_FLAGS   "${CMAKE_C_FLAGS}   -mstrict-align -ftree-vectorize")
      set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -mstrict-align -ftree-vectorize")
    else(${MACHINE} MATCHES "arm-linux-gnueabihf")
      set(CMAKE_C_FLAGS   "${CMAKE_C_FLAGS}   -mssse3")
      set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -mssse3")
    endif(${MACHINE} MATCHES "arm-linux-gnueabihf")

I have aarch64, not arm, as I understand.

[shoomilka]

I replaced

# Add for ARM
set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -mfpu=neon -mfloat-abi=hard -ftree-vectorize -latomic")
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -mfpu=neon -mfloat-abi=hard -ftree-vectorize -latomic")

with the next:

# Add for Aarch
set(CMAKE_C_FLAGS   "${CMAKE_C_FLAGS}   -mstrict-align -ftree-vectorize")
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -mstrict-align -ftree-vectorize")

and it begin to work!

[congvmit]

@shoomilka It's very nice to hear that.

[shoomilka]

Unit tests run with the next output:
test cases: 14 | 2 passed | 12 failed
assertions: 184 | 171 passed | 13 failed

pyrealsense is not for aarch64, so I will make it from sources later. I hope I found an instruction for this.

[congvmit]

@shoomilka The pre-built pyrealsense is not for aarch64, you must re-compile and build from the source.
You can find the source code from this link: https://github.com/toinsson/pyrealsense