Build failure for ROS Iron: "Could not find a package configuration file provided by ament_cmake_flake8"

[130s]

Reported at ros/rosdistro#37815 (comment) thanks to @Yadunund

14:15:20 CMake Error at CMakeLists.txt:10 (find_package):
14:15:20   By not providing "Findament_cmake_flake8.cmake" in CMAKE_MODULE_PATH this
14:15:20   project has asked CMake to find a package configuration file provided by
14:15:20   "ament_cmake_flake8", but CMake did not find one.
14:15:20 
14:15:20   Could not find a package configuration file provided by
14:15:20   "ament_cmake_flake8" with any of the following names:
14:15:20 
14:15:20     ament_cmake_flake8Config.cmake
14:15:20     ament_cmake_flake8-config.cmake
14:15:20 
14:15:20   Add the installation prefix of "ament_cmake_flake8" to CMAKE_PREFIX_PATH or
14:15:20   set "ament_cmake_flake8_DIR" to a directory containing one of the above
14:15:20   files.  If "ament_cmake_flake8" provides a separate development package or
14:15:20   SDK, be sure it has been installed.

[130s]

I'll see if I can find time in a few days but it'll be great if anyone can tackle (I should be able to spend time for review).

[130s]

Ticket is about ROS Iron, but wondered why on other distros this wasn't reported?

In fact I do see the same error took place on Humble https://build.ros2.org/job/Hdev__smach__ubuntu_jammy_amd64/1/console (although this link is the build BEFORE the change in rosdistro was merged ros/rosdistro#37813, I just assume the same issue happens sooner or later on Humble, and rolling).

[130s]

I confirmed the issue by removing the package in question then build (in this example rocker isn't needed at all, it can be a pure docker run but you get the idea).

Reproducible footage

export LINUX_DISTRO=jammy
export ROS_DISTRO=iron
export DOCKERIMG=ros:iron-ros-base
export PATH_LOCAL_WS=/home/noodle/ros/executive_smach

rocker --nvidia --x11 --network host  \
  --volume $PATH_LOCAL_WS/ros/executive_smach:/cws/src/executive_smach \
  --volume /dev:/dev  \
  --  \
  $DOCKERIMG bash

Now in the Docker container

export DIR_CWS=/cws && cd $DIR_CWS
source /opt/ros/iron/setup.bash
apt update && rosdep update && rosdep install --from-paths src --ignore-src -r -y

apt purge ros-iron-ament-cmake-flake8 && apt autoremove

colcon build
Starting >>> smach   
Starting >>> smach_msgs
/usr/lib/python3/dist-packages/setuptools/dist.py:723: UserWarning: Usage of dash-separated 'script-dir' will not be supported in future versions. Please use the underscore name 'script_dir' instead
  warnings.warn(
/usr/lib/python3/dist-packages/setuptools/dist.py:723: UserWarning: Usage of dash-separated 'install-scripts' will not be supported in future versions. Please use the underscore name 'install_scripts' instead
  warnings.warn(
--- stderr: smach                                                         
/usr/lib/python3/dist-packages/setuptools/dist.py:723: UserWarning: Usage of dash-separated 'script-dir' will not be supported in future versions. Please use the underscore name 'script_dir' instead
  warnings.warn(
/usr/lib/python3/dist-packages/setuptools/dist.py:157: UserWarning: newlines not allowed and will break in the future
  warnings.warn("newlines not allowed and will break in the future")
/usr/lib/python3/dist-packages/setuptools/command/install.py:34: SetuptoolsDeprecationWarning: setup.py install is deprecated. Use build and pip and other standards-based tools.
  warnings.warn(
/cws/install/smach/lib/python3.10/site-packages/smach/state_machine.py:77: SyntaxWarning: "is not" with a literal. Did you mean "!="?
  return {k:v for (k, v) in self.__dict__.items() if k is not "_state_transitioning_lock"}
---
Finished <<< smach [0.42s]
--- stderr: smach_msgs
CMake Error at CMakeLists.txt:10 (find_package):
  By not providing "Findament_cmake_flake8.cmake" in CMAKE_MODULE_PATH this
  project has asked CMake to find a package configuration file provided by
  "ament_cmake_flake8", but CMake did not find one.

  Could not find a package configuration file provided by
  "ament_cmake_flake8" with any of the following names:

    ament_cmake_flake8Config.cmake
    ament_cmake_flake8-config.cmake

  Add the installation prefix of "ament_cmake_flake8" to CMAKE_PREFIX_PATH or
  set "ament_cmake_flake8_DIR" to a directory containing one of the above
  files.  If "ament_cmake_flake8" provides a separate development package or
  SDK, be sure it has been installed.

---
Failed   <<< smach_msgs [0.45s, exited with code 1]

Summary: 1 package finished [0.55s]
  1 package failed: smach_msgs
  2 packages had stderr output: smach smach_msgs
  2 packages not processed

[130s]

I confirmed the issue by removing the package in question then build (in this example rocker isn't needed at all, it can be a pure docker run but you get the idea).

Just a follow-up comment to how I verified the issue #111 (comment), it looks like purging ament_cmake_flake8 execerbate ros2' build pipeline unnecessarilly. Even with the suggested fix #112, colcon build still fails shedding the same error.

:
Starting >>> smach_msgs
/usr/lib/python3/dist-packages/setuptools/dist.py:723: UserWarning: Usage of dash-separated 'script-dir' will not be supported in future versions. Please use the underscore name 'script_dir' instead
  warnings.warn(
/usr/lib/python3/dist-packages/setuptools/dist.py:723: UserWarning: Usage of dash-separated 'install-scripts' will not be supported in future versions. Please use the underscore name 'install_scripts' instead
  warnings.warn(
--- stderr: smach                                                         
/usr/lib/python3/dist-packages/setuptools/dist.py:723: UserWarning: Usage of dash-separated 'script-dir' will not be supported in future versions. Please use the underscore name 'script_dir' instead
  warnings.warn(
/usr/lib/python3/dist-packages/setuptools/dist.py:157: UserWarning: newlines not allowed and will break in the future
  warnings.warn("newlines not allowed and will break in the future")
/usr/lib/python3/dist-packages/setuptools/command/install.py:34: SetuptoolsDeprecationWarning: setup.py install is deprecated. Use build and pip and other standards-based tools.
  warnings.warn(
/cws/install/smach/lib/python3.10/site-packages/smach/state_machine.py:77: SyntaxWarning: "is not" with a literal. Did you mean "!="?
  return {k:v for (k, v) in self.__dict__.items() if k is not "_state_transitioning_lock"}
---
Finished <<< smach [0.41s]
--- stderr: smach_msgs                         
CMake Error at /opt/ros/iron/share/rosidl_generator_py/cmake/rosidl_generator_py_generate_interfaces.cmake:335 (find_package):
  By not providing "Findament_cmake_flake8.cmake" in CMAKE_MODULE_PATH this
  project has asked CMake to find a package configuration file provided by
  "ament_cmake_flake8", but CMake did not find one.

  Could not find a package configuration file provided by
  "ament_cmake_flake8" with any of the following names:

    ament_cmake_flake8Config.cmake
    ament_cmake_flake8-config.cmake

  Add the installation prefix of "ament_cmake_flake8" to CMAKE_PREFIX_PATH or
  set "ament_cmake_flake8_DIR" to a directory containing one of the above
  files.  If "ament_cmake_flake8" provides a separate development package or
  SDK, be sure it has been installed.
Call Stack (most recent call first):
  /opt/ros/iron/share/ament_cmake_core/cmake/core/ament_execute_extensions.cmake:48 (include)
  /opt/ros/iron/share/rosidl_cmake/cmake/rosidl_generate_interfaces.cmake:316 (ament_execute_extensions)
  CMakeLists.txt:15 (rosidl_generate_interfaces)


---
Failed   <<< smach_msgs [1.04s, exited with code 1]

Summary: 1 package finished [1.14s]
  1 package failed: smach_msgs
  2 packages had stderr output: smach smach_msgs
  2 packages not processed

My guess is that somewhere in rosidl_generate_interfaces pipeline the ament_flake8 pkg is depended?