CMakeLists.txt

# When you build ROS by yourself, do NOT have multiple version of
# Python development packages (libpython3.XX-dev).
#
# Because packages in ROS use either
#
#     find_package(Python3 REQUIRED COMPONENTS Development)
# or
#     find_package(Python3 REQUIRED COMPONENTS Interpreter)
#
# These two give you a different version if you have a different
# version of python3.XX-dev from /usr/bin/python3.
#
# If you see something like the following, this could be the case.
#
#     CMake Error at /usr/share/cmake-3.28/Modules/FindPackageHandleStandardArgs.cmake:230 (message):
#       Could NOT find Python3 (missing: Development Development.Module
#       Development.Embed) (found version "3.12")
#
# This happends when your /usr/bin/python3 is "3.11" but you have
# libpython3.12-dev.
#
#     $ rm -rf builddir && cmake -B builddir
#     -- The C compiler identification is GNU 13.2.0
#     -- The CXX compiler identification is GNU 13.2.0
#     -- Detecting C compiler ABI info
#     -- Detecting C compiler ABI info - done
#     -- Check for working C compiler: /usr/lib/ccache/cc - skipped
#     -- Detecting C compile features
#     -- Detecting C compile features - done
#     -- Detecting CXX compiler ABI info
#     -- Detecting CXX compiler ABI info - done
#     -- Check for working CXX compiler: /usr/lib/ccache/c++ - skipped
#     -- Detecting CXX compile features
#     -- Detecting CXX compile features - done
#     -- Found Python3: /usr/include/python3.12 (found version "3.12.2") found components: Development Development.Module Development.Embed
#     -- Found Python3: /usr/bin/python3 (found version "3.11.7") found components: Interpreter
#     -- Configuring done (0.4s)
#     -- Generating done (0.0s)
#     -- Build files have been written to: /tmp/foo/builddir

cmake_minimum_required(VERSION 3.28)
project(check-pythons)
find_package(Python3 REQUIRED COMPONENTS Development)
find_package(Python3 REQUIRED COMPONENTS Interpreter)