updated build system

CMakeLists.txt

@@ -58,6 +58,10 @@ if(PROJECT_IS_MINGW)
   endif()
 endif()
 
+if (PROJECT_ENABLE_V2_ERRORS)
+  add_definitions(-DPROJECT_ENABLE_V2_ERRORS)
+endif()
+
 include(cmake/settings.cmake)
 
 include(cmake/flags.cmake)
@@ -143,6 +147,7 @@ endif()
       -DPROJECT_COPYRIGHT=${PROJECT_COPYRIGHT}
       -DPROJECT_DESC=${PROJECT_DESC}
       -DPROJECT_DIST_DIR=${PROJECT_DIST_DIR}
+      -DPROJECT_ENABLE_V2_ERRORS=${PROJECT_ENABLE_V2_ERRORS}
       -DPROJECT_ENABLE_WIN32_LONG_PATH_NAMES=${PROJECT_ENABLE_WIN32_LONG_PATH_NAMES}
       -DPROJECT_ENABLE_BACKWARD_CPP=${PROJECT_ENABLE_BACKWARD_CPP}
       -DPROJECT_ENABLE_CPP_HTTPLIB=${PROJECT_ENABLE_CPP_HTTPLIB}