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Set hints to find the python version we actually want. (#785)
The comment in the commit explains the reasoning behind it. Signed-off-by: Chris Lalancette <[email protected]>
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‎rosidl_generator_c/cmake/rosidl_generator_c_generate_interfaces.cmake‎

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@@ -92,6 +92,22 @@ rosidl_write_generator_arguments(
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ROS_INTERFACE_FILES "${_target_sources}"
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)
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# By default, without the settings below, find_package(Python3) will attempt
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# to find the newest python version it can, and additionally will find the
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# most specific version. For instance, on a system that has
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# /usr/bin/python3.10, /usr/bin/python3.11, and /usr/bin/python3, it will find
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# /usr/bin/python3.11, even if /usr/bin/python3 points to /usr/bin/python3.10.
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# The behavior we want is to prefer the "system" installed version unless the
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# user specifically tells us othewise through the Python3_EXECUTABLE hint.
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# Setting CMP0094 to NEW means that the search will stop after the first
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# python version is found. Setting Python3_FIND_UNVERSIONED_NAMES means that
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# the search will prefer /usr/bin/python3 over /usr/bin/python3.11. And that
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# latter functionality is only available in CMake 3.20 or later, so we need
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# at least that version.
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cmake_minimum_required(VERSION 3.20)
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cmake_policy(SET CMP0094 NEW)
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set(Python3_FIND_UNVERSIONED_NAMES FIRST)
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find_package(Python3 REQUIRED COMPONENTS Interpreter)
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set(disable_description_codegen_arg)

‎rosidl_generator_cpp/cmake/rosidl_generator_cpp_generate_interfaces.cmake‎

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@@ -94,6 +94,22 @@ rosidl_write_generator_arguments(
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TYPE_DESCRIPTION_TUPLES "${${rosidl_generate_interfaces_TARGET}__DESCRIPTION_TUPLES}"
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)
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# By default, without the settings below, find_package(Python3) will attempt
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# to find the newest python version it can, and additionally will find the
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# most specific version. For instance, on a system that has
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# /usr/bin/python3.10, /usr/bin/python3.11, and /usr/bin/python3, it will find
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# /usr/bin/python3.11, even if /usr/bin/python3 points to /usr/bin/python3.10.
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# The behavior we want is to prefer the "system" installed version unless the
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# user specifically tells us othewise through the Python3_EXECUTABLE hint.
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# Setting CMP0094 to NEW means that the search will stop after the first
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# python version is found. Setting Python3_FIND_UNVERSIONED_NAMES means that
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# the search will prefer /usr/bin/python3 over /usr/bin/python3.11. And that
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# latter functionality is only available in CMake 3.20 or later, so we need
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# at least that version.
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cmake_minimum_required(VERSION 3.20)
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cmake_policy(SET CMP0094 NEW)
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set(Python3_FIND_UNVERSIONED_NAMES FIRST)
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find_package(Python3 REQUIRED COMPONENTS Interpreter)
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add_custom_command(

‎rosidl_generator_type_description/cmake/rosidl_generator_type_description_generate_interfaces.cmake‎

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@@ -12,6 +12,22 @@
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# See the License for the specific language governing permissions and
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# limitations under the License.
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# By default, without the settings below, find_package(Python3) will attempt
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# to find the newest python version it can, and additionally will find the
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# most specific version. For instance, on a system that has
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# /usr/bin/python3.10, /usr/bin/python3.11, and /usr/bin/python3, it will find
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# /usr/bin/python3.11, even if /usr/bin/python3 points to /usr/bin/python3.10.
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# The behavior we want is to prefer the "system" installed version unless the
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# user specifically tells us othewise through the Python3_EXECUTABLE hint.
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# Setting CMP0094 to NEW means that the search will stop after the first
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# python version is found. Setting Python3_FIND_UNVERSIONED_NAMES means that
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# the search will prefer /usr/bin/python3 over /usr/bin/python3.11. And that
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# latter functionality is only available in CMake 3.20 or later, so we need
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# at least that version.
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cmake_minimum_required(VERSION 3.20)
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cmake_policy(SET CMP0094 NEW)
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set(Python3_FIND_UNVERSIONED_NAMES FIRST)
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find_package(Python3 REQUIRED COMPONENTS Interpreter)
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set(_output_path "${CMAKE_CURRENT_BINARY_DIR}/rosidl_generator_type_description/${PROJECT_NAME}")

‎rosidl_typesupport_introspection_c/cmake/rosidl_typesupport_introspection_c_generate_interfaces.cmake‎

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@@ -76,6 +76,22 @@ rosidl_write_generator_arguments(
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TARGET_DEPENDENCIES ${target_dependencies}
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)
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# By default, without the settings below, find_package(Python3) will attempt
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# to find the newest python version it can, and additionally will find the
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# most specific version. For instance, on a system that has
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# /usr/bin/python3.10, /usr/bin/python3.11, and /usr/bin/python3, it will find
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# /usr/bin/python3.11, even if /usr/bin/python3 points to /usr/bin/python3.10.
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# The behavior we want is to prefer the "system" installed version unless the
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# user specifically tells us othewise through the Python3_EXECUTABLE hint.
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# Setting CMP0094 to NEW means that the search will stop after the first
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# python version is found. Setting Python3_FIND_UNVERSIONED_NAMES means that
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# the search will prefer /usr/bin/python3 over /usr/bin/python3.11. And that
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# latter functionality is only available in CMake 3.20 or later, so we need
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# at least that version.
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cmake_minimum_required(VERSION 3.20)
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cmake_policy(SET CMP0094 NEW)
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set(Python3_FIND_UNVERSIONED_NAMES FIRST)
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find_package(Python3 REQUIRED COMPONENTS Interpreter)
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add_custom_command(

‎rosidl_typesupport_introspection_cpp/cmake/rosidl_typesupport_introspection_cpp_generate_interfaces.cmake‎

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Original file line numberDiff line numberDiff line change
@@ -76,6 +76,22 @@ rosidl_write_generator_arguments(
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TARGET_DEPENDENCIES ${target_dependencies}
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)
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# By default, without the settings below, find_package(Python3) will attempt
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# to find the newest python version it can, and additionally will find the
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# most specific version. For instance, on a system that has
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# /usr/bin/python3.10, /usr/bin/python3.11, and /usr/bin/python3, it will find
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# /usr/bin/python3.11, even if /usr/bin/python3 points to /usr/bin/python3.10.
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# The behavior we want is to prefer the "system" installed version unless the
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# user specifically tells us othewise through the Python3_EXECUTABLE hint.
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# Setting CMP0094 to NEW means that the search will stop after the first
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# python version is found. Setting Python3_FIND_UNVERSIONED_NAMES means that
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# the search will prefer /usr/bin/python3 over /usr/bin/python3.11. And that
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# latter functionality is only available in CMake 3.20 or later, so we need
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# at least that version.
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cmake_minimum_required(VERSION 3.20)
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cmake_policy(SET CMP0094 NEW)
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set(Python3_FIND_UNVERSIONED_NAMES FIRST)
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find_package(Python3 REQUIRED COMPONENTS Interpreter)
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add_custom_command(

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