SKIP: FAILED #version 310 es precision mediump float; int x_1 = 0; void main_1() { int x_2 = x_1; return; } void tint_symbol(uint x_1_param) { x_1 = int(x_1_param); main_1(); } void main() { tint_symbol(uint(gl_SampleID)); return; } Error parsing GLSL shader: ERROR: 0:16: 'gl_SampleID' : required extension not requested: GL_OES_sample_variables ERROR: 0:16: '' : compilation terminated ERROR: 2 compilation errors. No code generated.