This test creates some geometry and tessellation geometry shaders that contains unsized output block arrays

~~~
#version 430 core
#extension GL_ARB_enhanced_layouts : require

layout(points)                           in;
layout(triangle_strip, max_vertices = 4) out;

layout (location = 2) out DBZ {
    vec4 goku;
    vec4 gohan[4];
    vec4 goten;
    layout (location = 1) vec4 chichi;
    vec4 pan;
} dbz[];

in  vec4 tes_gs[];
out vec4 gs_fs;
~~~

According to GLSL 4.30 specification, section 4.3.9 (Interface Blocks)

"Geometry shader input blocks must be declared as arrays and follow the array declaration and linking rules for all geometry shader inputs. All other input and output block arrays must specify an array size."

Though I didn't found it in the spec, Mesa code suggests this also applies to tessellation evaluation shaders.

https://github.com/KhronosGroup/VK-GL-CTS/issues/56

This was my analysis. I believe the issue is that it's expecting a location layout conflict, but it doesn't due to the variables being unused. You may be interested in perusing my analysis of the various other enhanced_layouts failures on the VK-GL-CTS github issues list.

I have just sent a series that fixes this (along with a bunch of other piglit and CTS tests for enhanced layouts):

https://lists.freedesktop.org/archives/mesa-dev/2017-October/173503.html

It looks like Iago's series landed, and this works now.  Marking fixed.