fix backward compatibility mode on macos

CMakeLists.txt

@@ -119,8 +119,8 @@ endif()
 if(gRPC_BACKWARDS_COMPATIBILITY_MODE)
   add_definitions(-DGPR_BACKWARDS_COMPATIBILITY_MODE)
   if (_gRPC_PLATFORM_MAC)
-    # CMAKE_OSX_DEPLOYMENT_TARGET
-    add_definitions(-mmacosx-version-min=10.7)
+    # some C++11 constructs not supported before OS X 10.9
+    set(CMAKE_OSX_DEPLOYMENT_TARGET 10.9)
   endif()
 endif()
 

templates/CMakeLists.txt.template

@@ -168,8 +168,8 @@
   if(gRPC_BACKWARDS_COMPATIBILITY_MODE)
     add_definitions(-DGPR_BACKWARDS_COMPATIBILITY_MODE)
     if (_gRPC_PLATFORM_MAC)
-      # CMAKE_OSX_DEPLOYMENT_TARGET
-      add_definitions(-mmacosx-version-min=10.7)
+      # some C++11 constructs not supported before OS X 10.9
+      set(CMAKE_OSX_DEPLOYMENT_TARGET 10.9)
     endif()
   endif()
 

tools/run_tests/artifacts/build_artifact_csharp.sh

@@ -20,8 +20,7 @@ cd "$(dirname "$0")/../../.."
 mkdir -p cmake/build
 cd cmake/build
 
-# -DgRPC_BACKWARDS_COMPATIBILITY_MODE=ON
-cmake -DCMAKE_BUILD_TYPE=RelWithDebInfo -DgRPC_BUILD_TESTS=OFF "${CMAKE_ARCH_OPTION}" ../..
+cmake -DCMAKE_BUILD_TYPE=RelWithDebInfo -DgRPC_BACKWARDS_COMPATIBILITY_MODE=ON -DgRPC_BUILD_TESTS=OFF "${CMAKE_ARCH_OPTION}" ../..
 make grpc_csharp_ext
 cd ../..