removed skbuild cmake modules. Instead, they are looked for or supplied

CMakeLists.txt

@@ -1,4 +1,5 @@
 cmake_minimum_required(VERSION "3.14")
+cmake_policy(SET CMP0148 OLD) # To suppress a warning emerging from scikit-build
 
 project(Clima LANGUAGES Fortran C VERSION "0.3.11")
 
@@ -8,8 +9,10 @@ set(CMAKE_Fortran_MODULE_DIRECTORY "${CMAKE_BINARY_DIR}/modules")
 include(cmake/CPM.cmake)
 
 # options
-option(SKBUILD "Should be ON of being build by skbuild, 
-and OFF of being build by regular cmake" OFF)
+if (NOT DEFINED SKBUILD)
+  set(SKBUILD OFF CACHE STRING )
+endif()
+message(STATUS "The project is built using scikit-build: ${SKBUILD}")
 
 option(BUILD_EXECUTABLES "if ON, then will build the
 Fortran executables" ON)
@@ -30,7 +33,17 @@ add_subdirectory(tests)
 
 if (BUILD_PYTHON_CLIMA)
   if (NOT SKBUILD)
-    set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${PROJECT_SOURCE_DIR}/cmake/")
+    if (NOT DEFINED SKBUILD_CMAKE_MODULE_DIR)
+      # Here, we try to find scikit-build cmake modules
+      find_package(Python COMPONENTS Development)
+      set(SKBUILD_CMAKE_MODULE_DIR "${Python_LIBRARY_DIRS}/python${Python_VERSION_MAJOR}.${Python_VERSION_MINOR}/site-packages/skbuild/resources/cmake")
+    endif()
+    if (EXISTS ${SKBUILD_CMAKE_MODULE_DIR})
+      message(STATUS "Scikit-build CMake modules: ${SKBUILD_CMAKE_MODULE_DIR}")
+    else()
+      message(FATAL_ERROR "Failed to find scikit-build CMake modules in directory: ${SKBUILD_CMAKE_MODULE_DIR}")
+    endif()
+    set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} ${SKBUILD_CMAKE_MODULE_DIR})
   endif()
 
   find_package(PythonExtensions REQUIRED)