Compiling error on Raspberry Pi 4

[cjffly]

Hi, while I am trying to compile the latest mavsdk (0.38.2) on my rPi 4, I had this error when I try to install:

mavsdk/src/core/mavlink_parameters.cpp:279:23: error: too few arguments to function ‘uint16_t mavlink_msg_param_ext_request_read_pack(uint8_t, uint8_t, mavlink_message_t*, uint8_t, uint8_t, const char*, int16_t, uint8_t)’
  279 |                     -1);
      |                       ^

...
mavsdk/src/third_party/mavlink/include/mavlink/v2.0/common/mavlink_msg_param_ext_request_read.h:63:24: note: declared here
   63 | static inline uint16_t mavlink_msg_param_ext_request_read_pack(uint8_t system_id, uint8_t component_id, mavlink_message_t* msg,
      |                        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~



At global scope:
cc1plus: note: unrecognized command-line option ‘-Wno-unknown-warning-option’ may have been intended to silence earlier diagnostics
make[2]: *** [src/core/CMakeFiles/mavsdk.dir/build.make:252: src/core/CMakeFiles/mavsdk.dir/mavlink_parameters.cpp.o] Error 1
make[1]: *** [CMakeFiles/Makefile2:752: src/core/CMakeFiles/mavsdk.dir/all] Error 2
make: *** [Makefile:150: all] Error 2

I thought my gcc version was 8 so I took 4 hours to get the latest gcc version (10.2.0), and this error is still there. Any idea what cause this error?

[JonasVautherin]

Sounds like you use mavsdk as a git submodule, and you updated it without updating its submodules (i.e. mavlink). Could it be?

[julianoes]

@cjffly try git submodule update --init --recursive in MAVSDK.

[cjffly]

@julianoes Thanks, that helps to get through this issue.

However, anther issue popup:

[ 22%] Linking CXX shared library libmavsdk_camera.so
/usr/bin/ld: cannot find -ltinyxml2
collect2: error: ld returned 1 exit status
make[2]: *** [src/plugins/camera/CMakeFiles/mavsdk_camera.dir/build.make:151: src/plugins/camera/libmavsdk_camera.so.0.38.2] Error 1
make[1]: *** [CMakeFiles/Makefile2:833: src/plugins/camera/CMakeFiles/mavsdk_camera.dir/all] Error 2
make: *** [Makefile:150: all] Error 2

Seems like it couldn't find the -ltinyxml2. I am sure I've tinyxml2 installed through vcpkg, and I've added include($ENV{VCPKG_ROOT}/scripts/buildsystems/vcpkg.cmake) in the CMakeLists.txt

[JonasVautherin]

Can you show the cmake commands you use to configure and build?

I wonder why it fails at build time, I would have expected it to fail at configure time, here :thinking:

[cjffly]

I am using the standard configure and build commands:

cmake -DCMAKE_BUILD_TYPE=Debug -DBUILD_SHARED_LIBS=ON -Bbuild/default -H.
cmake --build build/default

Here is the part from configure output which contains tinyxml2:

-- Preparing external project "tinyxml2" with args:
-- -- -DCMAKE_INSTALL_PREFIX:PATH=......mavsdk/build/default/third_party/install
-- -- -DCMAKE_TOOLCHAIN_FILE:PATH=
-- -- -DCMAKE_BUILD_TYPE=Debug
-- -- -DCMAKE_POSITION_INDEPENDENT_CODE=ON
-- -- -DBUILD_SHARED_LIBS=OFF
-- -- -DBUILD_TESTS=OFF
-- Configuring done
-- Generating done
CMake Warning:
  Manually-specified variables were not used by the project:

    DEPLOYMENT_TARGET
    ENABLE_STRICT_TRY_COMPILE
    PLATFORM


-- Build files have been written to: ......mavsdk/build/default/third_party/tinyxml2
Scanning dependencies of target tinyxml2
[ 12%] Creating directories for 'tinyxml2'
[ 25%] Performing download step (download, verify and extract) for 'tinyxml2'
-- Downloading...
   dst='......mavsdk/build/default/third_party/tinyxml2/tinyxml2/src/7.1.0.tar.gz'
   timeout='none'
-- Using src='https://github.com/leethomason/tinyxml2/archive/7.1.0.tar.gz'
-- [download 100% complete]
-- Downloading... done
-- extracting...
     src='......mavsdk/build/default/third_party/tinyxml2/tinyxml2/src/7.1.0.tar.gz'
     dst='......mavsdk/build/default/third_party/tinyxml2/tinyxml2/src/tinyxml2'
-- extracting... [tar xfz]
-- extracting... [analysis]
-- extracting... [rename]
-- extracting... [clean up]
-- extracting... done
[ 50%] No update step for 'tinyxml2'
[ 50%] No patch step for 'tinyxml2'
[ 62%] Performing configure step for 'tinyxml2'
CMake Deprecation Warning at CMakeLists.txt:11 (cmake_policy):
  The OLD behavior for policy CMP0063 will be removed from a future version
  of CMake.

  The cmake-policies(7) manual explains that the OLD behaviors of all
  policies are deprecated and that a policy should be set to OLD only under
  specific short-term circumstances.  Projects should be ported to the NEW
  behavior and not rely on setting a policy to OLD.


-- The C compiler identification is GNU 10.2.0
-- The CXX compiler identification is GNU 10.2.0
-- Check for working C compiler: /usr/bin/cc
-- Check for working C compiler: /usr/bin/cc - 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/c++
-- Check for working CXX compiler: /usr/bin/c++ - works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Configuring done
-- Generating done
-- Build files have been written to: ......mavsdk/build/default/third_party/tinyxml2/tinyxml2/src/tinyxml2-build
[ 75%] Performing build step for 'tinyxml2'
Scanning dependencies of target tinyxml2
[ 50%] Building CXX object CMakeFiles/tinyxml2.dir/tinyxml2.cpp.o
[100%] Linking CXX static library libtinyxml2d.a
[100%] Built target tinyxml2
[ 87%] Performing install step for 'tinyxml2'
[100%] Built target tinyxml2
Install the project...
-- Install configuration: "Debug"
-- Installing: ......mavsdk/build/default/third_party/install/lib/libtinyxml2d.a
-- Installing: ......mavsdk/build/default/third_party/install/include/tinyxml2.h
-- Installing: ......mavsdk/build/default/third_party/install/lib/pkgconfig/tinyxml2.pc
-- Installing: ......mavsdk/build/default/third_party/install/lib/cmake/tinyxml2/tinyxml2Config.cmake
-- Installing: ......mavsdk/build/default/third_party/install/lib/cmake/tinyxml2/tinyxml2ConfigVersion.cmake
-- Installing: ......mavsdk/build/default/third_party/install/lib/cmake/tinyxml2/tinyxml2Targets.cmake
-- Installing: ......mavsdk/build/default/third_party/install/lib/cmake/tinyxml2/tinyxml2Targets-debug.cmake
[100%] Completed 'tinyxml2'
[100%] Built target tinyxml2
-- The C compiler identification is GNU 10.2.0
-- The CXX compiler identification is GNU 10.2.0
-- Check for working C compiler: /usr/bin/cc
-- Check for working C compiler: /usr/bin/cc - 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/c++
-- Check for working CXX compiler: /usr/bin/c++ - works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Detecting CXX compile features
-- Detecting CXX compile features - done

[cjffly]

Can you show the cmake commands you use to configure and build?

I wonder why it fails at build time, I would have expected it to fail at configure time, here 🤔

OK, seems I figure out that I add my include($ENV{VCPKG_ROOT}/scripts/buildsystems/vcpkg.cmake) at the wrong CMakeLists.txt. Previous I thought I should add this into the one under MAVSDK root folder. Now I add the "include vcpkg" to MAVSDK/src/CMakeLists.txt, and build is success.

However, if I don't have vcpkg this will be a problem, so I guess it still needs some kind of fix.

[JonasVautherin]

You are using the default SUPERBUILD=ON value, and hence MAVSDK builds tinyxml2 for you. It should not required vcpkg in that mode.

Can you show the cmake output related to this line? It sounds like for some reason, it does not find the tinyxml2 from the superbuild, and hence fallsback to vcpkg.

My first guess is that in Debug mode, Windows calls it libtinyxml2d.a instead of libtinyxml2.a. Maybe there is something to do in the find module.

Can you try a release build to check if that works?

[cjffly]

@JonasVautherin When you mean

Can you show the cmake output related to this line?

Which command output are you referring to? Is it cmake -DCMAKE_BUILD_TYPE=Debug -DBUILD_SHARED_LIBS=ON -Bbuild/default -H. or cmake --build build/default? If the first, I did posted above, that is the output related to tinyxml2, I did see it download and builds for me, it just couldn't find it.

By the way, I am using raspberry pi 4, not Windows, not sure

Windows calls it libtinyxml2d.a instead of libtinyxml2.a. Maybe there is something to do in the find module.

is true. But I will try in release build and let you know the result.

Update: Build with Release without the help of vcpkg works, using the the following:

 cmake -Bbuild/default -DCMAKE_BUILD_TYPE=Release -H.
 cmake --build build/default -j8

[JonasVautherin]

Right, sorry I got confused, it's now Windows :see_no_evil:.

So what has changed recently is that we used to build all the dependencies in Release mode, and now we propagate the CMAKE_BUILD_TYPE to them. And tinyxml2 does this thing of renaming the debug output file...

Which command output are you referring to?

I'm looking for some output like this? I.e. when find_package or pkgconfig finds the library, usually it outputs something like "found tinyxml2 here: ".

Maybe the find module should look for tinyxml2d somewhere if CMAKE_BUILD_TYPE=Debug... :thinking:. Would you mind having a look at that?