[onert] Suggestion to modify unnecessary code according to pybind11 update

[jaemaning]

Background

Recently, I discovered that a long-standing bug in pybind11 has been fixed. This fix eliminates the need to directly import Python development components (libs, headers) from various Linux environments.

Reference to the current implementation:

ONE/runtime/onert/api/python/CMakeLists.txt

Lines 5 to 26 in 30d45e8

	# CMakeLists.txt
	# refer to https://github.com/Samsung/ONE/issues/11368
	# Tell pybind11 where the target python installation is
	#
	# FindPythonLibs is deprecated since 3.12, and recommand to use FindPython.
	# But on cross compile, FindPython is not working for target environment
	# For workaround, use PythonLibs
	find_package(PythonLibs REQUIRED)
	set(PYTHON_MODULE_PREFIX "lib" CACHE INTERNAL "Cross python lib prefix")
	set(PYTHON_MODULE_EXTENSION ".so" CACHE INTERNAL "Cross python lib extension")
	# Disable pybind11 python search mechanism
	set(PYTHONLIBS_FOUND TRUE CACHE INTERNAL "")
	# Install pybind11
	nnfw_find_package(Pybind11 REQUIRED)
	if(NOT Pybind11_FOUND)
	message(STATUS "Build onert/python: FAILED (Pybind11 is missing)")
	return()
	endif()

Proposed Change

Given this fix, I suggest updating the code to the following:

# Install pybind11
nnfw_find_package(Pybind11 REQUIRED)
if(NOT Pybind11_FOUND)
  message(STATUS "Build onert/python: FAILED (Pybind11 is missing)")
  return()
endif()

Opinion

I would like to know your thoughts on this proposed change.

Reference

For more details on the bug fix, please see: pybind/pybind11#4805

[hseok-oh]

Thanks your suggestion. Then we need to use more latest pybind11 version, right? (not currently using v2.11.1)

[jaemaning]

I understand that ONE is currently using pybind v2.11.1.

ONE/infra/cmake/packages/Pybind11SourceConfig.cmake

Lines 10 to 11 in 0d7274f

	envoption(EXTERNAL_DOWNLOAD_SERVER "https://github.com")
	envoption(PYBIND11_URL ${EXTERNAL_DOWNLOAD_SERVER}/pybind/pybind11/archive/v2.11.1.tar.gz)

And the above application requires the use of pybind 2.12.0 releasing version.

Pybind11 Version 2.12.0 - bug fixes List

If it is okay to use the currently released version of pybind11 v2.12.0, I will test it.

Reference

https://github.com/pybind/pybind11/releases

[hseok-oh]

Based on release note, this feature works on cmake 3.18+.
Since we are using cmake 3.16.3 (ubuntu 20.04's default cmake version), we cannot use this feature.

[jaemaning]

oh, I didn't check the cmake version
Thanks for checking this

[hseok-oh]

@jaemaning Thank you for inform us about this. When we ready to upgrade cmake version, we can use this feature.