[ROS2] rclcpp linking error and correct way to handle dependencies

edit

Hi, I'm trying to migrate my ROS 1 libraries to ROS 2 and have some trouble with setting up the packages.

I read the ament CMake documentation and this thread, but I'm still not sure what the recommended way to deal with dependencies is. It would be great if someone could give feedback on the CMake files, e.g. if there are missing or superfluous lines or something should be done differently.

At the moment, colcon build fails with the following error:

Starting >>> bridge
--- stderr: bridge                             
/usr/bin/ld: -lrclcpp not found
collect2: error: ld returned 1 exit status

CMakeLists.txt of package bridge:

cmake_minimum_required(VERSION 3.5)
project(bridge)
find_package(ament_cmake REQUIRED)
find_package(rclcpp REQUIRED)
find_package(rl2_com REQUIRED)
find_package(bridge_support REQUIRED)

add_executable(bridge src/main.cpp)
target_link_libraries(bridge rl2_com::rl2_com)
ament_target_dependencies(bridge rclcpp rl2_com bridge_support)

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

ament_package()

CMakeLists.txt of package bridge_support (header-only library):

cmake_minimum_required(VERSION 3.5)
project(bridge_support)
find_package(ament_cmake REQUIRED)

install(
  DIRECTORY include/
  DESTINATION include
)

ament_export_include_directories(include)
ament_package()

CMakeLists.txt of package rl2_com:

cmake_minimum_required(VERSION 3.5)
project(rl2_com)

find_package(ament_cmake REQUIRED)
find_package(rl2_logging REQUIRED)

include_directories(include)

add_library(rl2_com src/com.cpp)
target_link_libraries(rl2_com rl2_logging::rl2_logging)
ament_target_dependencies(rl2_com rl2_logging)
ament_export_dependencies(rl2_logging)
ament_export_interfaces(export_rl2_com HAS_LIBRARY_TARGET)

install(
  DIRECTORY include/
  DESTINATION include
)

install(
  TARGETS rl2_com
  EXPORT export_rl2_com
  LIBRARY DESTINATION lib
  ARCHIVE DESTINATION lib
  RUNTIME DESTINATION bin
  INCLUDES DESTINATION include
)

ament_package()

CMakeLists.txt of package rl2_logging:

cmake_minimum_required(VERSION 3.5)
project(rl2_logging)
find_package(ament_cmake REQUIRED)
find_package(rclcpp REQUIRED)

include_directories(include)

add_library(rl2_logging src/log.cpp)
target_link_libraries(rl2_logging rclcpp)
ament_target_dependencies(rl2_logging rclcpp)
ament_export_dependencies(rclcpp)
ament_export_interfaces(export_rl2_logging HAS_LIBRARY_TARGET)

install(
  DIRECTORY include/
  DESTINATION include
)

install(
  TARGETS rl2_logging
  EXPORT export_rl2_logging
  LIBRARY DESTINATION lib
  ARCHIVE DESTINATION lib
  RUNTIME DESTINATION bin
  INCLUDES DESTINATION include
)

ament_package()

The package.xml files contain <depend>XXXXXX</depend> directives for the required packages.

Please note: For better readability, I omitted the following lines in each CMakeLists.txt:

# Default to C99
if(NOT CMAKE_C_STANDARD)
  set(CMAKE_C_STANDARD 99)
endif()

# Default to C++17
if(NOT CMAKE_CXX_STANDARD)
  set(CMAKE_CXX_STANDARD 17)
endif()

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