Oops.

.appveyor.yml

@@ -22,7 +22,7 @@ install:
 
     cd ../Build
 
-    cmake -G "%VS_GENERATOR%" -DBUILD_SHARED_LIBS=%BUILD_SHARED_LIBS% -DBUILD_SAMPLES=%BUILD_SAMPLES% -DSKIP_DIRECTX_SAMPLES .
+    cmake -G "%VS_GENERATOR%" -DBUILD_SHARED_LIBS=%BUILD_SHARED_LIBS% -DBUILD_SAMPLES=%BUILD_SAMPLES% -DSKIP_DIRECTX_SAMPLES=ON .
 build:
   parallel: true
   verbosity: minimal