[CMake] Explicitly use Python3 everywhere.

CMakeLists.txt

@@ -255,7 +255,7 @@ option(OGS_CHECK_HEADER_COMPILATION "Check header for standalone compilation."
        OFF)
 
 option(OGS_USE_PYTHON "Interface with Python" OFF)
-if(OGS_USE_PYTHON AND NOT Python_FOUND)
+if(OGS_USE_PYTHON AND NOT Python3_FOUND)
     message(FATAL_ERROR "Python not found but required for OGS_USE_PYTHON=ON!")
 endif()
 
@@ -356,10 +356,10 @@ add_subdirectory(MeshLib)
 add_subdirectory(MeshGeoToolsLib)
 add_subdirectory(NumLib)
 
-if (OGS_BUILD_PROCESS_ComponentTransport
-    OR OGS_BUILD_PROCESS_RichardsComponentTransport
-    OR OGS_BUILD_PROCESS_RichardsComponentTransport
-    OR OGS_BUILD_PROCESS_HeatTransportBHE)
+if(OGS_BUILD_PROCESS_ComponentTransport
+   OR OGS_BUILD_PROCESS_RichardsComponentTransport
+   OR OGS_BUILD_PROCESS_RichardsComponentTransport
+   OR OGS_BUILD_PROCESS_HeatTransportBHE)
     add_subdirectory(ChemistryLib)
 endif()
 

ProcessLib/BoundaryCondition/Python/CMakeLists.txt

 add_library(ProcessLibBoundaryConditionPython
-            PythonBoundaryCondition.cpp PythonBoundaryCondition.h
+            PythonBoundaryCondition.cpp
+            PythonBoundaryCondition.h
             PythonBoundaryConditionLocalAssembler.h
             PythonBoundaryConditionPythonSideInterface.h
             BHEInflowPythonBoundaryCondition.h
@@ -18,13 +19,14 @@ target_link_libraries(ProcessLibBoundaryConditionPython
                              MeshLib
                              NumLib
                              logog
-                             ${Python_LIBRARIES}
+                             ${Python3_LIBRARIES}
                       PRIVATE pybind11::pybind11)
 
 # For the embedded Python module
 add_library(ProcessLibBoundaryConditionPythonModule
             PythonBoundaryConditionModule.cpp PythonBoundaryConditionModule.h
-            BHEInflowPythonBoundaryConditionModule.cpp BHEInflowPythonBoundaryConditionModule.h)
+            BHEInflowPythonBoundaryConditionModule.cpp
+            BHEInflowPythonBoundaryConditionModule.h)
 if(BUILD_SHARED_LIBS)
     install(TARGETS ProcessLibBoundaryConditionPythonModule
             LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR})

ProcessLib/SourceTerms/Python/CMakeLists.txt

@@ -18,7 +18,7 @@ target_link_libraries(ProcessLibSourceTermPython
                              MeshLib
                              NumLib
                              logog
-                             ${Python_LIBRARIES}
+                             ${Python3_LIBRARIES}
                       PRIVATE pybind11::pybind11)
 
 # For the embedded Python module

ThirdParty/CMakeLists.txt

@@ -67,10 +67,10 @@ endif()
 if(OGS_USE_PYTHON)
     # pybind11 uses old CMake find functionality, pass variables to use
     # the same Python installation.
-    find_package(Python COMPONENTS Interpreter Development REQUIRED)
-    set(PYTHON_INCLUDE_DIR ${Python_INCLUDE_DIRS} CACHE STRING "" FORCE)
-    set(PYTHON_LIBRARIES ${Python_LIBRARIES} CACHE STRING "" FORCE)
-    set(PYTHON_EXECUTABLE ${Python_EXECUTABLE} CACHE FILEPATH "" FORCE)
+    set(PYTHON_INCLUDE_DIR ${Python3_INCLUDE_DIRS} CACHE STRING "" FORCE)
+    set(PYTHON_LIBRARIES ${Python3_LIBRARIES} CACHE STRING "" FORCE)
+    set(PYTHON_EXECUTABLE ${Python3_EXECUTABLE} CACHE FILEPATH "" FORCE)
+    set(PYBIND11_PYTHON_VERSION ${Python3_VERSION})
 
     add_subdirectory(pybind11)
 
@@ -89,9 +89,9 @@ if(OGS_USE_PYTHON)
         endif()
 
         include(${VTK_MODULES_DIR}/vtkPython.cmake)
-        if (NOT "${vtkPython_LIBRARIES}" STREQUAL "${Python_LIBRARIES}")
+        if (NOT "${vtkPython_LIBRARIES}" STREQUAL "${Python3_LIBRARIES}")
             message(SEND_ERROR "Mismatch between VTK's and OpenGeoSys' Python "
-                "libraries: ${vtkPython_LIBRARIES} vs. ${Python_LIBRARIES}. "
+                "libraries: ${vtkPython_LIBRARIES} vs. ${Python3_LIBRARIES}. "
                 "This will lead to compilation or linking errors. "
                 "You can fix this error by using the same Python version for "
                 "OpenGeoSys as VTK is built with.")

scripts/cmake/Coverage.cmake

@@ -22,7 +22,7 @@ else()
     message(STATUS "No lcov coverage report generated because lcov or genhtml was not found.")
 endif()
 
-if(Python_EXECUTABLE)
+if(Python3_EXECUTABLE)
     setup_target_for_coverage_gcovr_xml(
         NAME testrunner_coverage_cobertura
         EXECUTABLE ${CMAKE_COMMAND} --build . --target tests

scripts/cmake/DocumentationSetup.cmake

@@ -50,7 +50,7 @@ doxygen_add_docs(doc
     ${PROJECT_SOURCE_DIR}/
     ${PROJECT_BINARY_DIR}/DocAux/dox)
 
-if (BASH_TOOL_PATH AND Python_EXECUTABLE)
+if (BASH_TOOL_PATH AND Python3_EXECUTABLE)
     set(doc_use_external_tools TRUE)
 else()
     set(doc_use_external_tools FALSE)

scripts/cmake/Find.cmake

@@ -9,7 +9,11 @@ find_program(GPROF_PATH gprof DOC "GNU profiler gprof" QUIET)
 
 find_program(CPPCHECK_TOOL_PATH cppcheck)
 
-find_package(Python COMPONENTS Interpreter Development)
+if(OGS_USE_PYTHON)
+    find_package(Python3 COMPONENTS Interpreter Development REQUIRED)
+else()
+    find_package(Python3 COMPONENTS Interpreter)
+endif()
 
 # Find bash itself ...
 find_program(BASH_TOOL_PATH bash

scripts/cmake/packaging/Pack.cmake

@@ -112,7 +112,7 @@ endif()
 
 if(OGS_USE_PYTHON)
     if(WIN32)
-        file(GLOB PYTHON_RUNTIME_LIBS "${Python_RUNTIME_LIBRARY_DIRS}/*.dll")
+        file(GLOB PYTHON_RUNTIME_LIBS "${Python3_RUNTIME_LIBRARY_DIRS}/*.dll")
         message(STATUS "Install Python: ${PYTHON_RUNTIME_LIBS}")
         install(FILES ${PYTHON_RUNTIME_LIBS} DESTINATION bin)
     else()