alexe's profile - activity

Happened to me too when I was accidentally publishing messages with illegal values, in my case NaNs in a PoseStamped. On

That solved it, thank you so much! Follow-up question (since I'm a bit of a noob): Why does this only fail at run time a

That solved it, thank you so much! Follow-up question (since I'm a bit of a noob): Why does this only fail at run time a

I'm trying to use the tf2_ros::BufferInterface::transform method on a PointCloud2 message like so (tf_buffer_ is a tf2_ros::Buffer object):

void someMethod(const sensor_msgs::PointCloud2ConstPtr& input_cloud)
{
  const auto transformed_cloud = tf_buffer_.transform<sensor_msgs::PointCloud2>(*input_cloud,
      some_frame_id, ros::Duration(0.1));

  ... do some stuff ...
}

The code compiles fine, but fails with a symbol lookup error during run time:

undefined symbol: ros::Time const& tf2::getTimestamp<sensor_msgs::PointCloud2_<std::allocator<void> > >(sensor_msgs::PointCloud2_<std::allocator<void> > const&)

I have no idea what is going on. I tried to include all sorts of packages (tf2, tf2_ros, tf2_msgs, tf2_sensor_msgs, geometry_msgs, sensor_msgs) in both my CMakeLists and my package.xml, but that doesn't help.

It's worthwhile mentioning that I'm using the same tf2_ros::Buffer object before this point in the program to transform a geometry_msgs::PointStamped message, which has the same frame_id as the point cloud, into the same target frame, and there it works just fine. Just for this PointCloud2 message it seems to fail.

That solved it, thank you so much! Follow-up question (since I'm a bit of a noob): Why does this only fail at run time a

Undefined symbol error when using tf2_ros::BufferInterface::transform I'm trying to use the tf2_ros::BufferInterface::tr

But why would you need to use pcl_ros::transformPointCloud if there are no PCL types involved? That seems to make no sen

But why would you need to use pcl_ros::transformPointCloud if there are no PCL types involved? That seems to make no sen

Undefined symbol error when using tf2_ros::BufferInterface::transform I'm trying to use the tf2_ros::BufferInterface::tr

Hey there,

the default python version I use on my Ubuntu 16.04 machine is 3.6 (Anaconda) and I'm trying to setup my catkin workspace. When I run catkin_make, I get an error that has been described in a few other questions here (such as here and here):

ImportError: "from catkin_pkg.package import parse_package" failed: No module named 'catkin_pkg'
Make sure that you have installed "catkin_pkg", it is up to date and on the PYTHONPATH.

The suggestions in the other questions don't help me, as this is about a more general problem:

How can I run ROS (Kinetic in my case) when my default python version is 3.x?

I want to make it so that ROS uses python 2.7, but I want to keep python 3.6 as my default python version.

Is that possible? If yes, how do I do that?

This is my default python version:

$ python -V
Python 3.6.0 :: Anaconda 4.3.1 (64-bit)

And my sys.path:

$ python -c 'import sys; print(sys.path)'
['', '/opt/ros/kinetic/lib/python2.7/dist-packages', '/home/xyz/anaconda3/lib/python36.zip', '/home/xyz/anaconda3/lib/python3.6', '/home/xyz/anaconda3/lib/python3.6/lib-dynload', '/home/xyz/anaconda3/lib/python3.6/site-packages', '/home/xyz/anaconda3/lib/python3.6/site-packages/Sphinx-1.5.1-py3.6.egg', '/home/xyz/anaconda3/lib/python3.6/site-packages/setuptools-27.2.0-py3.6.egg']

I tried to simply add /usr/lib/python2.7/ to my ~/.bashrc, but that doesn't work. I can't even source the .bashrc because of syntax errors in all files with python 2 syntax.

My logic was that if I simply add all python directories, version 2.x and 3.x, to my PYTHONPATH, then any application (such as ROS) can always find the right modules it needs. But it doesn't seem to work like that, or at least simply adding python paths to .bashrc. doesn't work.

Weirdly, the path '/opt/ros/kinetic/lib/python2.7/dist-packages' is already in there, but it is /usr/lib/python2.7/dist-packages that contains catkin_pkg and some other important packages and modules.

Any help is very much appreciated!

Thanks for that info! The fact that ROS doesn't support Python 3 in 2018 is honestly absolutely ridiculous.

Thanks, the build and devel folders were exactly the issue! After deleting them, building worked as expected :)

I created a workspace catkin_ws_01 and created some packages inside it.

Then I duplicated that same workspace folder to create catkin_ws_02 and made some changes to the packages inside. Then I deleted the original workspace folder catkin_ws_01.

Now when I try to run catkin_make from inside catkin_ws_02, it gives me the following error message:

CMake Error: The source directory "/home/blabla/catkin_ws_01/src" does not exist.

This means that catkin_make still refers to catkin_ws_01 even though I am executing the command from within catkin_ws_02.

What is going on and how can I fix this?

@ahendrix I'm sorry, when I deleted the question I didn't even realize that there had already been an answer.

I copied a workspace and now catkin_make doesn't work I created a workspace catkin_ws_01 and created some packages insid

Creating a conda environment with python 2.7 and then PIP installing catking_pkg and running catkin_make from within that environment solves the issue above, but now I'm getting a new error described here.

I'm having the same problem above and this does not solve the problem, not finding catkin_pkg is not the problem here. It is already installed via PIP in my case and I'm still getting this error.