require at least MacOS 10.13

cmake/BornAgain/MacOS.cmake

@@ -13,8 +13,8 @@ execute_process(COMMAND sw_vers "-productVersion"
     OUTPUT_VARIABLE MACOSX_MINOR OUTPUT_STRIP_TRAILING_WHITESPACE)
 message(STATUS "Found a Mac OS X System ${MACOSX_VERSION}, minor ${MACOSX_MINOR}")
 
-if((${MACOSX_VERSION} EQ 10) AND (${MACOSX_MINOR} LESS 13))
-    message(FATAL_ERROR "Found a MacOS X < 10.13, which is unsupported")
+if((${MACOSX_VERSION} EQ 10) AND (${MACOSX_MINOR} LESS 15))
+    message(FATAL_ERROR "Found a MacOS X < 10.15, which is unsupported")
 endif()
 
 #TODO: check haveconfig and rpath -> set rpath true
@@ -27,8 +27,8 @@ endif()
 set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS}")
 string(APPEND CMAKE_SHARED_LIBRARY_CREATE_C_FLAGS " -m64")
 string(APPEND CMAKE_SHARED_LIBRARY_CREATE_CXX_FLAGS " -m64")
-string(APPEND CMAKE_CXX_FLAGS " -m64 -mmacosx-version-min=10.13 -I${CMAKE_SOURCE_DIR}/Wrap")
-string(APPEND CMAKE_C_FLAGS " -m64 -mmacosx-version-min=10.13")
+string(APPEND CMAKE_CXX_FLAGS " -m64 -mmacosx-version-min=10.15 -I${CMAKE_SOURCE_DIR}/Wrap")
+string(APPEND CMAKE_C_FLAGS " -m64 -mmacosx-version-min=10.15")
 string(APPEND CMAKE_C_LINK_FLAGS " -bind_at_load -m64")
 string(APPEND CMAKE_CXX_LINK_FLAGS " -bind_at_load -m64")