Fix CMake build for MacOS (OpenModelica#13895)

Author: perost

OMCompiler/SimulationRuntime/ParModelica/CMakeLists.txt

@@ -1,5 +1,9 @@
 
-if(CMAKE_VERSION VERSION_LESS "3.30")
+if(APPLE)
+  # MacPorts installs the Boost configuration file in a non-standard location,
+  # keep using the old FindBoost module for now.
+  find_package(Boost COMPONENTS graph chrono REQUIRED)
+elseif(CMAKE_VERSION VERSION_LESS "3.30")
   find_package(Boost COMPONENTS graph chrono REQUIRED)
 else()
   find_package(Boost CONFIG COMPONENTS graph chrono REQUIRED)

OMCompiler/SimulationRuntime/ParModelica/auto/CMakeLists.txt

@@ -1,6 +1,10 @@
 set(CMAKE_INSTALL_INCLUDEDIR ${CMAKE_INSTALL_INCLUDEDIR}/ParModelica/auto)
 
-if(CMAKE_VERSION VERSION_LESS "3.30")
+if(APPLE)
+  # MacPorts installs the Boost configuration file in a non-standard location,
+  # keep using the old FindBoost module for now.
+  find_package(Boost COMPONENTS graph chrono REQUIRED)
+elseif(CMAKE_VERSION VERSION_LESS "3.30")
   find_package(Boost COMPONENTS graph chrono REQUIRED)
 else()
   find_package(Boost CONFIG COMPONENTS graph chrono REQUIRED)

OMCompiler/SimulationRuntime/cpp/cmake_3.14.cmake

@@ -14,8 +14,12 @@ set(CMAKE_INSTALL_DEFAULT_COMPONENT_NAME simrtcpp)
 
 
 # Boost and a threading library are required for the CPP-runtime.
-if(CMAKE_VERSION VERSION_LESS "3.30")
-  find_package(Boost COMPONENTS program_options filesystem REQUIRED)
+if(APPLE)
+ # MacPorts installs the Boost configuration file in a non-standard location,
+ # keep using the old FindBoost module for now.
+ find_package(Boost COMPONENTS program_options filesystem REQUIRED)
+elseif(CMAKE_VERSION VERSION_LESS "3.30")
+ find_package(Boost COMPONENTS program_options filesystem REQUIRED)
 else()
   find_package(Boost CONFIG COMPONENTS program_options filesystem REQUIRED)
 endif()