removed accidental cmake 3.14 requirement (minimum is now 3.13)

CMakeLists.txt

@@ -1,7 +1,8 @@
 # Minimum cmake version:
 # - 3.12 is needed for https://cmake.org/cmake/help/latest/command/target_link_libraries.html#id8
 # - 3.12 is needed for https://cmake.org/cmake/help/latest/command/add_compile_definitions.html
-cmake_minimum_required(VERSION 3.12)
+# - 3.13 is needed to install targets that were created in other directories (https://cmake.org/cmake/help/latest/command/install.html)
+cmake_minimum_required(VERSION 3.13)
 
 project(fabm
   VERSION 2.0.1
@@ -86,9 +87,11 @@ endif()
 # Use solution folders in IDEs
 set_property(GLOBAL PROPERTY USE_FOLDERS ON)
 
+# Determine default installation directories (CMAKE_INSTALL_LIBDIR, CMAKE_INSTALL_INCLUDEDIR)
+include(GNUInstallDirs)
+
 # Add YAML parsing library, unless the yaml target was already defined by a parent CMakeLists.txt
 if(NOT TARGET yaml)
-  include(GNUInstallDirs)
   add_subdirectory("${CMAKE_CURRENT_LIST_DIR}/src/yaml" yaml EXCLUDE_FROM_ALL)
   set_property(TARGET yaml PROPERTY FOLDER fabm/yaml)
   install(DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/yaml/modules/\${BUILD_TYPE}/ DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/yaml)

src/CMakeLists.txt

@@ -216,14 +216,18 @@ endif()
 
 # Install FABM library and include files, unless the host overruled this.
 if (NOT DEFINED FABM_NO_LIBRARY_INSTALL)
-  install(TARGETS fabm EXPORT fabmConfig)
+  # Note: using an implicit destination for install(TARGETS ...) below,
+  # or TYPE instead of DESTINATION, requires cmake >= 3.14
+  install(TARGETS fabm
+    EXPORT fabmConfig
+    DESTINATION ${CMAKE_INSTALL_LIBDIR})
   install(DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/modules/\${BUILD_TYPE}/
-    TYPE INCLUDE)
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR})
   install(FILES
     ${CMAKE_CURRENT_LIST_DIR}/../include/fabm.h
     ${CMAKE_CURRENT_LIST_DIR}/../include/fabm_version.h
     ${CMAKE_CURRENT_LIST_DIR}/drivers/${FABM_HOST}/fabm_driver.h
-    TYPE INCLUDE)
+    DESTINATION ${CMAKE_INSTALL_INCLUDEDIR})
 endif()
 
 export(EXPORT fabmConfig)