rosidl does not support "ros2 interface show <actual srv name>" while using sub folder for srv sort

[Young-Yihang]

Generated by Generative AI

No response

Operating System:

Linux huan-ROG-Zephyrus-G16-GU605MI-GU605MI 6.8.0-94-generic #96-Ubuntu SMP PREEMPT_DYNAMIC Fri Jan 9 20:36:55 UTC 2026 x86_64 x86_64 x86_64 GNU/Linux

ROS version or commit hash:

jazzy

RMW implementation (if applicable):

rmw_fastrtps_cpp

RMW Configuration (if applicable):

No response

Client library (if applicable):

No response

'ros2 doctor --report' output

platform info : Linux-6.8.0-94-generic-x86_64-with-glibc2.39
release : 6.8.0-94-generic
processor : x86_64

RMW MIDDLEWARE
middleware name : rmw_fastrtps_cpp

ROS 2 INFORMATION
distribution name : jazzy
distribution type : ros2
distribution status : active
release platforms : {'ubuntu': ['noble']}

PACKAGE VERSIONS
ros-jazzy-rosidl-cmake : 4.6.7-1noble.20260121.190524

Steps to reproduce issue

1. using sub folders like "srv/my_category/Foo.srv"

Expected behavior

service_msgs dependencies would be added to build section

Actual behavior

could lead to service_msgs dependencies not added

Additional information

Steps to reproduce issue:

1. Create a minimal interfaces package with srv files in subdirectories

mkdir -p my_interfaces/srv/my_category
cat > my_interfaces/srv/my_category/MyService.srv << 'EOF'
string input

string output
EOF

cat > my_interfaces/CMakeLists.txt << 'EOF'
cmake_minimum_required(VERSION 3.22)
project(my_interfaces)

find_package(ament_cmake REQUIRED)
find_package(rosidl_default_generators REQUIRED)

rosidl_generate_interfaces(${PROJECT_NAME}
"srv/my_category/MyService.srv"
)

ament_package()
EOF

cat > my_interfaces/package.xml << 'EOF'

my_interfaces 0.0.1 Test package Test Apache-2.0 ament_cmake rosidl_default_generators rosidl_interface_packages EOF

2. Build - this will FAIL

colcon build --packages-select my_interfaces

Expected behavior:

Build succeeds. The service_msgs dependency should be automatically detected and added for .srv files regardless of directory structure, just like it works for srv/MyService.srv.

Actual behavior:

Build fails with:
KeyError: 'service_msgs'

Additional information:

Root cause is in rosidl_generate_interfaces.cmake lines 148-184. The code detects service files by checking if the parent directory name equals srv:

get_filename_component(_parent_dir "${_tuple_file}" DIRECTORY)
get_filename_component(_parent_dir ${_parent_dir} NAME)
...
elseif("${_parent_dir}" STREQUAL "srv")

• srv/MyService.srv → parent dir = srv ✅ works
• srv/my_category/MyService.srv → parent dir = my_category ❌ fails

Workaround: Manually add service_msgs dependency:
find_package(service_msgs REQUIRED)
rosidl_generate_interfaces(${PROJECT_NAME}
"srv/my_category/MyService.srv"
DEPENDENCIES service_msgs
)

Suggested fix: Check file extension instead of parent directory name, or check if path contains /srv/ or starts with srv/.