Skip to content

Extend backward_ros documentation #753

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
SteveMacenski merged 6 commits into from
Aug 6, 2025
Merged

Extend backward_ros documentation #753

Changes from all commits
Commits
Show all changes
6 commits
Select commit Hold shift + click to select a range
1185a05
Extend backward_ros documentation
Sushant-Chavan Aug 6, 2025
4da9dc8
Fix pre-commit checks
Sushant-Chavan Aug 6, 2025
f3b4f02
Update tutorials/docs/get_backtrace.rst
SteveMacenski Aug 6, 2025
8cfba67
Update tutorials/docs/get_backtrace.rst
SteveMacenski Aug 6, 2025
cae6e52
Update tutorials/docs/get_backtrace.rst
SteveMacenski Aug 6, 2025
a619735
Update tutorials/docs/get_backtrace.rst
SteveMacenski Aug 6, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
64 changes: 63 additions & 1 deletion tutorials/docs/get_backtrace.rst
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -253,4 +253,66 @@ Automatic backtrace on crash

The `backward-cpp <https://github.com/bombela/backward-cpp>`_ library provides beautiful stack traces, and the `backward_ros <https://github.com/pal-robotics/backward_ros/tree/foxy-devel>`_ wrapper simplifies its integration.

Just add it as a dependency and `find_package` it in your CMakeLists and the backward libraries will be injected in all your executables and libraries.
Navigation2 packages come pre-compiled with backward_ros, so you can automatically get a backtrace when a process crashes. This changes the logs to include a backtrace when the process crashes. Instead of getting a simple error log such as:

.. code-block:: bash

[planner_server-13] [INFO] [1754377648.634265021] [planner_server]: Computing path to goal....
[ERROR] [planner_server-13]: process has died [pid 165734, exit code -11, cmd '/opt/overlay_ws/src/navigation2/install/nav2_planner/lib/nav2_planner/planner_server --ros-args --log-level info --ros-args -r __node:=planner_server -r __ns:=/ -p use_sim_time:=True --params-file /tmp/launch_params_ou47e26i -r /tf:=tf -r /tf_static:=tf_static'].

You get a more detailed output with a backtrace, which can help you identify the source of the crash:

.. code-block:: bash

[planner_server-13] [INFO] [1754463292.960594359] [planner_server]: Computing path to goal....
[planner_server-13] Stack trace (most recent call last) in thread 130805:
[planner_server-13] #11 Object "/usr/lib/x86_64-linux-gnu/ld-linux-x86-64.so.2", at 0xffffffffffffffff, in
[planner_server-13] #10 Object "/usr/lib/x86_64-linux-gnu/libc.so.6", at 0x7509de004c3b, in
[planner_server-13] #9 Object "/usr/lib/x86_64-linux-gnu/libc.so.6", at 0x7509ddf77aa3, in
[planner_server-13] #8 Object "/usr/lib/x86_64-linux-gnu/libstdc++.so.6.0.33", at 0x7509de207db3, in
[planner_server-13] #7 Object "/opt/overlay_ws/src/navigation2/install/nav2_planner/lib/libplanner_server_core.so", at 0x7509de887ee7, in std::__future_base::_Async_state_impl<std::thread::_Invoker<std::tuple<nav2::SimpleActionServer<nav2_msgs::action::ComputePathToPose>::handle_accepted(std::shared_ptr<rclcpp_action::ServerGoalHandle<nav2_msgs::action::ComputePathToPose> >)::{lambda()#1}> >, void>::_M_run()
[planner_server-13] #6 Object "/usr/lib/x86_64-linux-gnu/libc.so.6", at 0x7509ddf7ced2, in
[planner_server-13] #5 Object "/opt/overlay_ws/src/navigation2/install/nav2_planner/lib/libplanner_server_core.so", at 0x7509de8825cc, in std::__future_base::_State_baseV2::_M_do_set(std::function<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> ()>*, bool*)
[planner_server-13] #4 Object "/opt/overlay_ws/src/navigation2/install/nav2_planner/lib/libplanner_server_core.so", at 0x7509de8bd380, in std::_Function_handler<std::unique_ptr<std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter> (), std::__future_base::_Task_setter<std::unique_ptr<std::__future_base::_Result<void>, std::__future_base::_Result_base::_Deleter>, std::thread::_Invoker<std::tuple<nav2::SimpleActionServer<nav2_msgs::action::ComputePathToPose>::handle_accepted(std::shared_ptr<rclcpp_action::ServerGoalHandle<nav2_msgs::action::ComputePathToPose> >)::{lambda()#1}> >, void> >::_M_invoke(std::_Any_data const&)
[planner_server-13] #3 Object "/opt/overlay_ws/src/navigation2/install/nav2_planner/lib/libplanner_server_core.so", at 0x7509de8bc2f4, in nav2::SimpleActionServer<nav2_msgs::action::ComputePathToPose>::work()
[planner_server-13] #2 Object "/opt/overlay_ws/src/navigation2/install/nav2_planner/lib/libplanner_server_core.so", at 0x7509de87b798, in nav2_planner::PlannerServer::computePlan()
[planner_server-13] #1 Object "/opt/overlay_ws/src/navigation2/install/nav2_planner/lib/libplanner_server_core.so", at 0x7509de873ce4, in nav2_planner::PlannerServer::publishPlan(nav_msgs::msg::Path_<std::allocator<void> > const&)
[planner_server-13] #0 Object "/opt/ros/rolling/lib/librclcpp_lifecycle.so", at 0x7509de62bf94, in rclcpp_lifecycle::SimpleManagedEntity::is_activated() const
[planner_server-13] Segmentation fault (Address not mapped to object [0x8])
[ERROR] [planner_server-13]: process has died [pid 129889, exit code -11, cmd '/opt/overlay_ws/src/navigation2/install/nav2_planner/lib/nav2_planner/planner_server --ros-args --log-level info --ros-args -r __node:=planner_server -r __ns:=/ -p use_sim_time:=True --params-file /tmp/launch_params_apyru5sq -r /tf:=tf -r /tf_static:=tf_static'].

Building Nav2 with the **RelWithDebInfo** or **Debug** build configuration allows for even more detailed backtraces including line numbers, file names, and relevant code blocks, in the backtrace:

.. code-block:: bash

[planner_server-13] [INFO] [1754377736.955537475] [planner_server]: Computing path to goal....
[planner_server-13] Stack trace (most recent call last) in thread 173639:
[planner_server-13] #11 Object "/usr/lib/x86_64-linux-gnu/ld-linux-x86-64.so.2", at 0xffffffffffffffff, in
[planner_server-13] #10 Object "/usr/lib/x86_64-linux-gnu/libc.so.6", at 0x795ea7ac8c3b, in
[planner_server-13] #9 Object "/usr/lib/x86_64-linux-gnu/libc.so.6", at 0x795ea7a3baa3, in

⋮

[planner_server-13] #2 Source "/opt/overlay_ws/src/navigation2/nav2_planner/src/planner_server.cpp", line 546, in computePlan [0x795ea8344363]
[planner_server-13] 543: }
[planner_server-13] 544:
[planner_server-13] 545: // Publish the plan for visualization purposes
[planner_server-13] > 546: publishPlan(result->path);
[planner_server-13] 547:
[planner_server-13] 548: auto cycle_duration = this->now() - start_time;
[planner_server-13] 549: result->planning_time = cycle_duration;
[planner_server-13] #1 Source "/opt/overlay_ws/src/navigation2/nav2_planner/src/planner_server.cpp", line 640, in publishPlan [0x795ea833df4a]
[planner_server-13] 637: auto msg = std::make_unique<nav_msgs::msg::Path>(path);
[planner_server-13] 638: RCLCPP_WARN(get_logger(), "Publishing plan with %zu poses", path.poses.size());
[planner_server-13] 639: plan_publisher_.reset();
[planner_server-13] > 640: if (plan_publisher_->is_activated() && plan_publisher_->get_subscription_count() > 0) {
[planner_server-13] 641: plan_publisher_->publish(std::move(msg));
[planner_server-13] 642: }
[planner_server-13] 643: }
[planner_server-13] #0 Object "/opt/ros/rolling/lib/librclcpp_lifecycle.so", at 0x795ea80f1f94, in rclcpp_lifecycle::SimpleManagedEntity::is_activated() const
[planner_server-13] Segmentation fault (Address not mapped to object [0x8])
[ERROR] [planner_server-13]: process has died [pid 172784, exit code -11, cmd '/opt/overlay_ws/src/navigation2/install/nav2_planner/lib/nav2_planner/planner_server --ros-args --log-level info --ros-args -r __node:=planner_server -r __ns:=/ -p use_sim_time:=True --params-file /tmp/launch_params_px13xl6j -r /tf:=tf -r /tf_static:=tf_static'].

If you want to enable automatic backtraces in your own packages, just add ``backward_ros`` as a dependency and ``find_package`` in your CMakeLists, then the backward libraries will be injected in all your executables and libraries.

**Note:** Currently, backward_ros does not work with ComposedNodes due to missing support in rclcpp. Until this `issue <https://github.com/ros2/rclcpp/issues/2396>`_ is resolved, launching the Nav2 stack with composition disabled (e.g. with a `use_composition:=False` launch argument) is required to get automatic backtraces.