And someone on the amigans forum said that the shader (myst3_box.vertex) itself is buggy, which i highly doubt
glslangvalidator errors on it with errors 'in for stage inputs': no supported for this version or enabled extensions.
Any more ideas?
EDIT:
It's obviuosly not the shader
GLSLangValidator is stricter than most OpenGL implementations. As "validator" and reference compiler, it checks whether the GLSL code is fully GLSL compliant. Most OpenGL implementations relax the rules and are more tolerant of mixing code from different GLSL versions.
The shader you posted uses GLSL v1.40+ features without specifying the GLSL version. That's why GLSLangValidator is giving "not supported in this version" errors. Adding "#version 140" at the top (without the quotes) should be enough to make GLSLangValidator accept it.
Of course, i wouldn't add something to just silence some third party program, but good to know the cause of it.
EDIT2:
I got confirmation that uniform boolean aren't supported yet.
Now to try and fix it locally.