To Reproduce:

1. Build and run the attached project on OSX with Metal.
2. Observe that when the scene is loaded the app freezes, with the printed in player.log:

"
Compilation failed:

<program source>:82:12: error: array type 'float4 [2]' is not assignable
tmpvar_1 = tmpvar_18;
~~~~~~~~ ^
<program source>:83:12: error: array type 'float4 [2]' is not assignable
tmpvar_2 = tmpvar_19;
~~~~~~~~ ^
"
and

"
"Metal: Error creating pipeline state: Compiler encountered an internal error
(null)
Receiving unhandled NULL exception
Obtained 12 stack frames.
"
3. The scene test only has the 'Diffuse_Vegetation' shader.

The same shader works fine on iOS Metal and with GLCORE on OSX.