Oups! Sorry about that... Fixed!

I'm still seeing the same undefined symbol error at runtime

/opt/ros/iron/lib/demo_nodes_cpp/listener: symbol lookup error: /home/yadunund/ws_rmw/install/rmw_zenoh_cpp/lib/librmw_zenoh_cpp.so: undefined symbol: _Z6z_dropI27zc_owned_liveliness_token_tEN15zenoh_drop_typeIT_E4typeEPS2_

In fact, on MacOS i'm unable to even compile with apple clang + ld linker

ld: Undefined symbols:
  zenoh_drop_type<zc_owned_liveliness_token_t>::type z_drop<zc_owned_liveliness_token_t>(zc_owned_liveliness_token_t*), referenced from:
      rcpputils::scope_exit<rmw_create_node::$_4>::~scope_exit() in rmw_zenoh.cpp.o
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make[2]: *** [librmw_zenoh_cpp.dylib] Error 1
make[1]: *** [CMakeFiles/rmw_zenoh_cpp.dir/all] Error 2
make: *** [all] Error 2
make: INTERNAL: Exiting with 11 jobserver tokens available; should be 10!
---
Failed   <<< rmw_zenoh_cpp [13.8s, exited with code 2]

/opt/ros/iron/lib/demo_nodes_cpp/listener: symbol lookup error: /home/yadunund/ws_rmw/install/rmw_zenoh_cpp/lib/librmw_zenoh_cpp.so: undefined symbol: Z6z_dropI27zc_owned_liveliness_token_tEN15zenoh_drop_typeIT_E4typeEPS2

Yeah, I'm seeing this as well with this PR in place. Not sure what is going on there.

Weird! The builds with both iron-ros-base and rolling-ros-base Docker images are passing here in Actions, as well as on my Ubuntu 22.04/Rolling VM.
Could it be related to compiler/linker version ?
Mine are gcc version 11.4.0 (Ubuntu 11.4.0-1ubuntu1~22.04) and GNU ld (GNU Binutils for Ubuntu) 2.38

Weird! The builds with both iron-ros-base and rolling-ros-base Docker images are passing here in Actions, as well as on my Ubuntu 22.04/Rolling VM. Could it be related to compiler/linker version ? Mine are gcc version 11.4.0 (Ubuntu 11.4.0-1ubuntu1~22.04) and GNU ld (GNU Binutils for Ubuntu) 2.38

To clarify, on Ubuntu 22.04 + Iron/Rolling, the packages build without any errors. But the linker error is thrown when the z_drop() is called on the liveliness token when we cleanup the node.
To reproduce this,

cd ~/ws_rmw
source install/setup.bash
export RMW_IMPLEMENTATION=rmw_zenoh_cpp
ros2 run demo_nodes_cpp listener

## Then terminal the node with Ctrl+C

/opt/ros/iron/lib/demo_nodes_cpp/listener: symbol lookup error: /home/yadunund/ws_rmw/install/rmw_zenoh_cpp/lib/librmw_zenoh_cpp.so: undefined symbol: _Z6z_dropI27zc_owned_liveliness_token_tEN15zenoh_drop_typeIT_E4typeEPS2_

Oh! OK, thanks for the clarification.
I managed to reproduce, and also saw the issue has actually been fixed in zenoh-c by eclipse-zenoh/zenoh-c#197.
The error disappeared for me after updating zenoh-c.