Error library linking libtf2.so from libtf2_ros.so ??

[mce16]

Description

**
i followed the instructions here (installed docker etc..)

https://index.ros.org/doc/ros2/Tutorials/Cross-compilation/#cross-compiling-examples-for-arm
and got what seemed to be the library linking error
**

Expected Behavior

** successfull built **

Actual Behavior

**
[172.192s] /usr/lib/gcc-cross/aarch64-linux-gnu/7/../../../../aarch64-linux-gnu/bin/ld: warning: libtf2.so, needed by /home/kk/cc_ws/ros2_ws/install/lib/libtf2_ros.so, not found (try using -rpath or -rpath-link)
[172.193s] /home/kk/cc_ws/ros2_ws/install/lib/libtf2_ros.so: undefined reference to tf2::BufferCore::canTransform(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::chrono::time_point<std::chrono::_V2::system_clock, std::chrono::duration<long, std::ratio<1l, 1000000000l> > > const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >*) const' [172.195s] /home/kk/cc_ws/ros2_ws/install/lib/libtf2_ros.so: undefined reference to tf2::BufferCore::canTransform(std::__cxx11::basic_string<char, std::char_traits, std::allocator > const&, std::chrono::time_point<std::chrono::_V2::system_clock, std::chrono::duration<long, std::ratio<1l, 1000000000l> > > const&, std::__cxx11::basic_string<char, std::char_traits, std::allocator > const&, std::chrono::time_point<std::chrono::_V2::system_clock, std::chrono::duration<long, std::ratio<1l, 1000000000l> > > const&, std::__cxx11::basic_string<char, std::char_traits, std::allocator > const&, std::__cxx11::basic_string<char, std::char_traits, std::allocator >*) const'
[172.196s] /home/kk/cc_ws/ros2_ws/install/lib/libtf2_ros.so: undefined reference to tf2::BufferCore::~BufferCore()' [172.196s] /home/kk/cc_ws/ros2_ws/install/lib/libtf2_ros.so: undefined reference to typeinfo for tf2::BufferCore'
[172.198s] /home/kk/cc_ws/ros2_ws/install/lib/libtf2_ros.so: undefined reference to tf2::BufferCore::lookupTransform(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::chrono::time_point<std::chrono::_V2::system_clock, std::chrono::duration<long, std::ratio<1l, 1000000000l> > > const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::chrono::time_point<std::chrono::_V2::system_clock, std::chrono::duration<long, std::ratio<1l, 1000000000l> > > const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) const' [172.201s] /home/kk/cc_ws/ros2_ws/install/lib/libtf2_ros.so: undefined reference to tf2::BufferCore::clear()'
[172.202s] /home/kk/cc_ws/ros2_ws/install/lib/libtf2_ros.so: undefined reference to tf2::BufferCore::setTransform(geometry_msgs::msg::TransformStamped_<std::allocator<void> > const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, bool)' [172.203s] /home/kk/cc_ws/ros2_ws/install/lib/libtf2_ros.so: undefined reference to tf2::BufferCore::allFramesAsYAMLabi:cxx11 const'
[172.203s] /home/kk/cc_ws/ros2_ws/install/lib/libtf2_ros.so: undefined reference to tf2::BufferCore::BufferCore(std::chrono::duration<long, std::ratio<1l, 1000000000l> >)' [172.203s] /home/kk/cc_ws/ros2_ws/install/lib/libtf2_ros.so: undefined reference to tf2::BufferCore::lookupTransform(std::__cxx11::basic_string<char, std::char_traits, std::allocator > const&, std::__cxx11::basic_string<char, std::char_traits, std::allocator > const&, std::chrono::time_point<std::chrono::_V2::system_clock, std::chrono::duration<long, std::ratio<1l, 1000000000l> > > const&) const'
[172.205s] collect2: error: ld returned 1 exit status

**

To Reproduce

**
colcon build --merge-install
--cmake-force-configure
--cmake-args
-DCMAKE_VERBOSE_MAKEFILE:BOOL=ON
-DCMAKE_TOOLCHAIN_FILE="$(pwd)/src/ros2/cross_compile/cmake-toolchains/generic_linux.cmake"
-DSECURITY=ON

**

System (please complete the following information)

• OS: [Ubuntu Bionic (WSL Windows 10)]

---

Additional context

** i searched libtf2.so and it actually can be found in the install/lib and the build directory **

[piraka9011]

Are you using the legacy instructions?
Can you use the new instructions documented in the README.md

[mce16]

I have the docker and qemu installed previously following the "legacy" instructions;

But here i was simply lost trying to follow the instructions here; after the line
pip3 install ros_cross_compile;

what do i do next? Invoking ros_cross_compile just return with command not found.

ros_cross_compile /path/to/my/workspace --arch aarch64 --os ubuntu --rosdistro eloquent

[emersonknapp]

It sounds like you do not have the pip bin directory on your PATH. On Ubuntu, it is likely to be ~/.local/bin/ for user-installed pip packages. Take a look at that dir and see if it contains ros_cross_compile - if so, then add it to PATH. Another likely location is /usr/local/bin

[mce16]

Ok, i have exported the path, more errors encountered.. something is missing, but i couldn't figure out what it is

see attached output;

cc.txt

[piraka9011]

Is the Docker daemon (dockerd) running? See the Docker docs for more info.
Also, is your user part of the docker user group?

sudo usermod -aG docker `whoami`

[emersonknapp]

Note that I have opened #202 to track an enhancement to fix the need for the above ^ troubleshooting in the future.

[mce16]

Hi, I am very sure my docker service was running (i had been building docker images successfully), and i had added myself to the docker group as well as per the installation steps.

Btw, i am running WSL with ubuntu bionic on Windows 10; now that you mentioned about dockerd (docker daemon), as i know it, docker daemon doen't work on WSL, so that could be the reason?
But as i mentioned, i have build and run docker images on my WSL too, i think it was connecting to remote docker daemon running through Docker for Windows, where the daemon exposed on tcp://localhost:2375 without TLS enabled.

Since i can build and run docker images here in WSL, if docker daemon is the issue, is there a way for the ros_cross_compile to work as well using the same logic as? What need to be done for it to work, since i can build and run docker images and containers in WSL .

As i understand it, the command will create the necessary docker image(s) and do ros2 download and setup inside the image, cross compile to arm etc and all that. I have initially tried to follow the 0.0.1 instructions which lead me to the library linking error as mentioned in the title.

[piraka9011]

It sounds like you need to explicitly specify the socket connection for Docker since it listens by default to a Unix socket (something like /var/run/docker.sock) but you stated the daemon is exposed on another socket.

Maybe this SO answer might help.

[mce16]

Hi, i think docker has no problem. It runs correctly and connect to daemon on the Windows 10 host,
via the socket connector for Docker, via $DOCKER_HOST variable, which points to localhost:2375

From my understanding, if DOCKER_HOST is set, then both docker and docker-compose will use that instead of /var/run/docker.sock.

It connects to the Daemon in Windows Docker Dekstop without problem, For instance, command docker -info gave me the required info, this command will not run if the docker can't connect to daemon. So on my WSL ubuntu, docker is definitely working correctly.

Is the ros_cross_compile trying to check if the dockerd is running in the WSL, or trying to start the dockerd on WSL ? or Was it trying to connect to the docker daemon on WSL or something like that ? Because i don't think there is any dockerd running in WSL, as Docker daemon cannot run directly on WSL, instead it uses the Docker CLI to connect to a remote Docker daemon running through Docker for Windows.

As ros_cross_compile is running on WSL, is there anything to skip the docker check if that is the issue? Because i am sure i can build and run docker images in WSL without problem, and my docker is connecting successfully to the docker daemon on Windows host.

[emersonknapp]

Sorry that we probably won't be able to provide any support with the legacy workflow. It is however a legitimate way of going about cross-compiling ROS code - the intent of this tool is to move towards automating that approach in a user friendly way.

To this issue:

Is the ros_cross_compile trying to check if the dockerd is running in the WSL, or trying to start the dockerd on WSL ?

ros_cross_compile is using the https://docker-py.readthedocs.io/en/stable/ library to invoke Docker - here's how it's currently constructing the low level client https://github.com/ros-tooling/cross_compile/blob/master/ros_cross_compile/docker_client.py#L66 - a naive url to the unix docker.sock

docker_api = docker.APIClient(base_url='unix://var/run/docker.sock')

We're using the low level docker.APIClient to get access to the live output streams to print in real time - looks like the normal DockerClient.from_env() explicitly looks at the DOCKER_HOST environment variable.

I've opened #204 to try and address this - I'm not sure yet if it works quite right, it would be useful if you could try it out and let me know if it helps with your situation.

[mce16]

This works.

However, i have another issue on WSL, which seemed to be related to mounting of directory.

see below output:

Command:

kk@xxxx:~/ros2_dashing$ ros_cross_compile $(pwd) --rosdistro dashing --arch armhf --os ubuntu

And yes, my src/ exists in ros2_dashing/

INFO:Docker Client: ---> bca57682f623
INFO:Docker Client:Step 7/10 : COPY gather_rosdeps.sh /root/
INFO:Docker Client: ---> Using cache
INFO:Docker Client: ---> c6e9b7235fdf
INFO:Docker Client:Step 8/10 : RUN mkdir -p /ws
INFO:Docker Client: ---> Using cache
INFO:Docker Client: ---> 485a72388d4f
INFO:Docker Client:Step 9/10 : WORKDIR /ws
INFO:Docker Client: ---> Using cache
INFO:Docker Client: ---> 0ebda28db54a
INFO:Docker Client:Step 10/10 : ENTRYPOINT ["/root/gather_rosdeps.sh"]
INFO:Docker Client: ---> Using cache
INFO:Docker Client: ---> 8d703e0fd24b
INFO:Docker Client:Successfully built 8d703e0fd24b
INFO:Docker Client:Successfully tagged ros_cross_compile:rosdep
INFO:Rosdep Gatherer:Running rosdep collector image on workspace /home/kk/ros2_dashing
INFO:Docker Client:+ '[' '!' -d ./src ']'
INFO:Docker Client:++ pwd
INFO:Docker Client:+ echo 'No src/ directory found at /ws, did you remember to mount your workspace?'
INFO:Docker Client:+ exit 1
INFO:Docker Client:No src/ directory found at /ws, did you remember to mount your workspace?
Traceback (most recent call last):
  File "/home/kk/.local/bin/ros_cross_compile", line 11, in 
    load_entry_point('ros-cross-compile', 'console_scripts', 'ros_cross_compile')()
  File "/home/kk/cc_src/cross_compile/ros_cross_compile/ros_cross_compile.py", line 172, in main
    cross_compile_pipeline(args)
  File "/home/kk/cc_src/cross_compile/ros_cross_compile/ros_cross_compile.py", line 163, in cross_compile_pipeline
    custom_data_dir=custom_data_dir)
  File "/home/kk/cc_src/cross_compile/ros_cross_compile/dependencies.py", line 84, in gather_rosdeps
    volumes=volumes,
  File "/home/kk/cc_src/cross_compile/ros_cross_compile/docker_client.py", line 142, in run_container
    image_name, exit_code, '', image_name, 'See above ^')
docker.errors.ContainerError: Command '' in image 'ros_cross_compile:rosdep' returned non-zero exit status 1: See above ^

Is the script trying to mount the specified ros2 workspace (the src/ and all its sub-directories) on the host into the docker image and the src/ failed to be mounted into the ws/ ?

[emersonknapp]

Yes, the script tries to mount the workspace onto the running container, but it appears that maybe it's not being successful. You can try this manual test, which is exactly what's happening under the hood

docker run \
  -v $(pwd):/ws \
  -e OWNER_USER=$(id -u) \
  -e ROSDISTRO=dashing \
  -e TARGET_OS=ubuntu:bionic \
  -e CUSTOM_SETUP='' \
  -e OUT_PATH=/ws/rosdep-test.bash \
  ros_cross_compile:rosdep

# should have created this file
cat rosdep-test.bash

And if that doesn't work, perhaps simply

docker run -it \
  -v $(pwd):/ws \
  --entrypoint=/bin/bash \
  ros_cross_compile:rosdep

# now try to list /ws and see what's there... it should be your workspace, src/ install/ build/ etc...

[emersonknapp]

Hello @mce16 did the above test yield any results for you? I've merged #204 which solves at least part of this issue - I will close this ticket for now, please reopen it if you still have something we need to work through. Thanks!