Why doesn't ros2 pkg list show the packages that I built?

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Hi, I am making a new ros2 node, but it is not showing up in the package list (similar to Why doesn't ros2 pkg list show the packages that I built?, but I believe I've sourced things correctly). I first build the minimal_publisher and minimal_subscriber and this worked fine. I then copied the pendulum_msgs demo to build a custom message (obstacle_msgs) and this works fine. Lastly I wanted to create a new node (obstacle_publisher) which based off minimal_publisher and have it use the newly defined message, but its not getting installed for ros2 to find (the first 3 example are).

CMakeList.txt:

cmake_minimum_required(VERSION 3.5)
project(obstacle_publisher)

# Default to C++14
if(NOT CMAKE_CXX_STANDARD)
  set(CMAKE_CXX_STANDARD 14)
endif()

if(CMAKE_COMPILER_IS_GNUCXX OR CMAKE_CXX_COMPILER_ID MATCHES "Clang")
  add_compile_options(-Wall -Wextra -Wpedantic)
endif()

find_package(ament_cmake REQUIRED)
find_package(rclcpp REQUIRED)
find_package(std_msgs REQUIRED)
find_package(obstacle_msgs REQUIRED)

include_directories("../dependencies/")

add_executable(obstacle_publisher obstaclePublisher.cpp obstacles.cpp)
ament_target_dependencies(obstacle_publisher rclcpp std_msgs obstacle_msgs)

install(TARGETS
  obstacle_publisher
  DESTINATION lib/${PROJECT_NAME}
)

ament_package()

package.xml:

<?xml version="1.0"?>
<package format="2">
  <name>obstacle_publisher</name>
  <version>0.0.0</version>
  <description>The obstacle_publisher package</description>

  <maintainer email="paul">Paul</maintainer>
  <license>TODO</license>
  <!-- <author email="paul">Paul</author> -->

  <buildtool_depend>catkin</buildtool_depend>
  <build_depend>message_generation</build_depend>
  <build_depend>roscpp</build_depend>
  <build_depend>std_msgs</build_depend>
  <build_depend>obstacle_msgs</build_depend>

  <build_export_depend>roscpp</build_export_depend>
  <build_export_depend>std_msgs</build_export_depend>

  <exec_depend>message_runtime</exec_depend>
  <exec_depend>roscpp</exec_depend>
  <exec_depend>std_msgs</exec_depend>
  <exec_depend>obstacle_msgs</exec_depend>

  <!-- The export tag contains other, unspecified, tags -->
  <export>
    <!-- Other tools can request additional information be placed here -->

  </export>
</package>

If I remove all the build data

rm -r build/ install/ log/

and then remake the project

colcon build --symlink-install

I get the following;

Starting >>> obstacle_msgs
[0.221s] WARNING:colcon.colcon_ros.prefix_path.ament:The path 
'/home/paul/code/eclipse_ws/ROS2/install/obstacle_msgs' in the environment variable AMENT_PREFIX_PATH doesn't 
exist
[0.221s] WARNING:colcon.colcon_ros.prefix_path.ament:The path 
'/home/paul/code/eclipse_ws/ROS2/install/minimal_subscriber' in the environment variable AMENT_PREFIX_PATH 
doesn't exist
[0.221s] WARNING:colcon.colcon_ros.prefix_path.ament:The path 
'/home/paul/code/eclipse_ws/ROS2/install/minimal_publisher' in the environment variable AMENT_PREFIX_PATH 
doesn't exist
[0.221s] WARNING:colcon.colcon_ros.prefix_path.catkin:The path 
'/home/paul/code/eclipse_ws/ROS2/install/obstacle_publisher' in the environment variable CMAKE_PREFIX_PATH 
doesn't exist
[0.221s] WARNING:colcon.colcon_ros.prefix_path.catkin:The path 
'/home/paul/code/eclipse_ws/ROS2/install/obstacle_msgs' in the environment variable CMAKE_PREFIX_PATH doesn't 
exist
[0.221s] WARNING:colcon.colcon_ros.prefix_path.catkin:The path 
'/home/paul/code/eclipse_ws/ROS2/install/minimal_subscriber' in the environment variable CMAKE_PREFIX_PATH 
doesn't exist
[0.221s] WARNING:colcon.colcon_ros.prefix_path.catkin:The path 
'/home/paul/code/eclipse_ws/ROS2/install/minimal_publisher' in the environment variable CMAKE_PREFIX_PATH 
doesn't exist
Starting >>> minimal_publisher
Starting >>> minimal_subscriber
Finished <<< minimal_publisher [4.67s]                                                             
Finished <<< minimal_subscriber [4.77s]                               
Finished <<< obstacle_msgs [7.55s]                       
Starting >>> obstacle_publisher
--- stderr: obstacle_publisher                               
CMake Warning:
  Manually-specified variables were not used by the project:

    CATKIN_INSTALL_INTO_PREFIX_ROOT


---
Finished <<< obstacle_publisher [4.60s]

Summary: 4 packages finished [12.3s]
  1 package had stderr output: obstacle_publisher

If I rebuild again ... (more)