cmake: Require at least CMake 3.26 and update Python dependency code

CMake 3.26 is the version available across all supported Fedora
releases, CentOS Stream 10, and Mageia Cauldron (to be Mageia 10).

To deal with the eventual removal of PythonInterp, switch over to
the Python3 module.

CMakeLists.txt

@@ -1,57 +1,57 @@
+cmake_minimum_required(VERSION 3.26)
+
 if(POLICY CMP0048)
 	cmake_policy(SET CMP0048 NEW)
 endif(POLICY CMP0048)
 
 project(dnfdragora VERSION 3.0.0 LANGUAGES NONE)
-cmake_minimum_required(VERSION 3.4)
 
 set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${CMAKE_SOURCE_DIR}/cmake")
 
-find_package(PythonInterp 3.4 REQUIRED)
+find_package(Python3 3.9 COMPONENTS Interpreter REQUIRED)
 find_package(Gettext)
 find_program(SPHINX_EXECUTABLE
-	NAMES	sphinx-build-${PYTHON_VERSION_MAJOR}.${PYTHON_VERSION_MINOR}
-		sphinx-build-${PYTHON_VERSION_MAJOR}
+	NAMES	sphinx-build-${Python3_VERSION_MAJOR}.${Python3_VERSION_MINOR}
+		sphinx-build-${Python3_VERSION_MAJOR}
 		sphinx-build)
 if(SPHINX_EXECUTABLE STREQUAL "SPHINX_EXECUTABLE-NOTFOUND")
 	message(STATUS "Could NOT find sphinx-build.")
 else(SPHINX_EXECUTABLE STREQUAL "SPHINX_EXECUTABLE-NOTFOUND")
 	message(STATUS "Found sphinx-build: ${SPHINX_EXECUTABLE}")
 endif(SPHINX_EXECUTABLE STREQUAL "SPHINX_EXECUTABLE-NOTFOUND")
 
-execute_process(COMMAND ${PYTHON_EXECUTABLE} -c "from distutils.sysconfig import get_python_lib; print(get_python_lib(), end='')" OUTPUT_VARIABLE PYTHON_INSTALL_DIR)
+execute_process(COMMAND ${Python3_EXECUTABLE} -c "from distutils.sysconfig import get_python_lib; print(get_python_lib(), end='')" OUTPUT_VARIABLE PYTHON_INSTALL_DIR)
 string(REGEX REPLACE "\n$" "" ${PYTHON_INSTALL_DIR} "${PYTHON_INSTALL_DIR}")
-execute_process(COMMAND ${PYTHON_EXECUTABLE} -c "import sys; sys.stdout.write('%s.%s' % (sys.version_info.major, sys.version_info.minor))" OUTPUT_VARIABLE PYTHON_MAJOR_DOT_MINOR_VERSION)
 message(STATUS "Python install dir is ${PYTHON_INSTALL_DIR}")
 
 option(CHECK_RUNTIME_DEPENDENCIES "Verify the presence of runtime-only dependencies?" ON)
 
 if(CHECK_RUNTIME_DEPENDENCIES)
-	include(FindPythonModule)
+	include(FindPython3Module)
 
 	# Find yui module
-	find_python_module(yui REQUIRED)
+	find_python3_module(yui REQUIRED)
 
 	# Find manatools module
-	find_python_module(manatools REQUIRED)
+	find_python3_module(manatools REQUIRED)
 
 	# Find libdnf5 module
-	find_python_module(libdnf5 REQUIRED)
+	find_python3_module(libdnf5 REQUIRED)
 
 	# Find yaml module
-	find_python_module(yaml REQUIRED)
+	find_python3_module(yaml REQUIRED)
 
 	# Find xdg module
-	find_python_module(xdg REQUIRED)
+	find_python3_module(xdg REQUIRED)
 
 	# Find cairosvg module
-	find_python_module(cairosvg REQUIRED)
+	find_python3_module(cairosvg REQUIRED)
 
 	# Find PIL module
-	find_python_module(PIL REQUIRED)
+	find_python3_module(PIL REQUIRED)
 
 	# Find pystray module
-	find_python_module(pystray REQUIRED)
+	find_python3_module(pystray REQUIRED)
 
 endif(CHECK_RUNTIME_DEPENDENCIES)
 

cmake/FindPythonModule.cmake → cmake/FindPython3Module.cmake

@@ -1,15 +1,15 @@
 # Find if a Python module is installed
 # Found at http://www.cmake.org/pipermail/cmake/2011-January/041666.html
-# To use do: find_python_module(PyQt5 REQUIRED)
-function(find_python_module module)
+# To use do: find_python3_module(PyQt6 REQUIRED)
+function(find_python3_module module)
 	string(TOUPPER ${module} module_upper)
 	if(NOT PY_${module_upper})
 		if(ARGC GREATER 1 AND ARGV1 STREQUAL "REQUIRED")
 			set(${module}_FIND_REQUIRED TRUE)
 		endif()
 		# A module's location is usually a directory, but for binary modules
 		# it's a .so file.
-		execute_process(COMMAND "${PYTHON_EXECUTABLE}" "-c" 
+		execute_process(COMMAND "${Python3_EXECUTABLE}" "-c" 
 			"import re, ${module}; print(re.compile('/__init__.py.*').sub('',${module}.__file__))"
 			RESULT_VARIABLE _${module}_status 
 			OUTPUT_VARIABLE _${module}_location