Shader compiler error on build

So I have a shader which outputs to single-float texture.

Code (csharp):

1.  
2. //Fragment Shader
3. float frag (v2f i) : SV_Target0 { // look output type here is float not float4
4.     float2 uv = i.scrPos.xy / i.scrPos.z;
5.  
6.     float sceneDepth = tex2D(DepthTexture, uv);
7.     float4 mask = tex2D(MaskTexture, uv);
8.  
9.     float lDepth = i.scrPos.z;
10.  
11.     return (lDepth - sceneDepth) * mask.r;
12. }
13.  

It works fine. When I build my project, it works fine in the build too but I get this error.

Code (csharp):

1.  
2. Shader error in 'Depth/DepthDifference': SV_Target0 must be a four-component vector at line 44 (on d3d11_9x)
3.  
4. Compiling Fragment program
5.  

Is it a bug in the compiler or my fault?

https://msdn.microsoft.com/en-us/li...tion_from_direct3d_9_to_direct3d_10_and_later states I can use simple float with SV_Target<N> semantic. And it works, so I think the error message should be fixed.

 

I realized SV_Target0 is dx11 semantic and fragment shader output can be plain float only for dx11.

So

Code (csharp):

1.  
2. #pragma only_renderers d3d11
3.  

solved the problem. So it's not a bug