Package Update

docs/troubleshooting.md

@@ -136,6 +136,24 @@ source activate_venv.sh
 pip install pexpect future
 ```
 
+source activate_venv.sh
+pip install pexpect future
+```
+
+### Build Failed (Missing catkin_pkg)
+
+**Symptoms:**
+- `ModuleNotFoundError: No module named 'catkin_pkg'` within `package_xml_2_cmake.py`
+- CMake configuration error at `ament_package_xml.cmake`
+
+**Solution:**
+This occurs when the virtual environment is missing ROS 2 build dependencies that are normally present in the system python but not in the venv.
+
+```bash
+source activate_venv.sh
+pip install catkin_pkg
+```
+
 ## WSL-Specific Issues
 
 ### Display Not Available