error: proc macro panicked

[marloncori]

After adding the two dependencies according to your instructions and after using the "cargo build" command I got the following at the very end of the process:

( ...)
"error: proc macro panicked
--> C:\Users\NUC\Desktop\rust\publisher\target\debug\build\rosrust_msg-313b65941bcfc194\out/messages.rs:2:1
|
2 | rosrust::rosmsg_include!(,IGNORE_BAD);
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= help: message: Failed to parse all message paths

error: could not compile rosrust_msg due to previous error
warning: build failed, waiting for other jobs to finish...
error: build failed"

How can we fix that?

By the way, I also cannot get how to run a publisher and subscriber or a client and a server at the same time, since there is no way to create a launch file to do so. Should I create two separate package with "cargo new --bin" and then add the two dependencies in each of the two generated Cargo.toml? And then if so, should I run "main.rs" in separate shells?

[kalinkochnev]

I had the same issue earlier today and here's how I fixed it

Specific the CMAKE_PREFIX_PATH or ROSRUST_MSG_PATH path variables.

1. To find where your ros installation is at, I would recommend searching for it with find / -name "ros". For me, my ROS installation was located in /opt/ros/, however that may be different for you since I was running mine in a container.

2. In order to get the prefix path, first run the setup script located here . /opt/ros/<ros_distro_here>/setup.sh. If you are using noetic, it sets a CMAKE_PREFIX_PATH variable. However, I had issues when running foxy instead since it assigned a different path variable instead of CMAKE_PREFIX_PATH. You should be able to compile and not get that error message anymore

3. When you run rosrust, this should then automatically discover where all the messages are that come with ROS. However, if you ran into the issue that there's a mismatch in type (when I tried with ROS foxy, it complained about there being different types for time) I decided to just specify only specific messages that I wanted with ROSRUST_MSG_PATH instead.

4. To specify that I wanted only the std_msgs, I did export ROSRUST_MSG_PATH=/opt/ros/<your_ros_distro>/share/std_msgs/

5. Reminder, you can specify multiple paths if you separate each path with a colon :

Finally, in my main.rs I had

mod msg {
    rosrust::rosmsg_include!(std_msgs/String);
}

I saw that there was also a pull request with a suggested warning to the user instead of panicking #165 to make it more clear what needs to be done. I highly suggest we merge this in since it was very confusing what was going on otherwise.

[AthulMuralidhar]

+1 on this one - I have the same issue as of now - looking forward to the release :)