diff -ru bedrock-vanilla-1.8.0/shaders/glsl/renderchunk.fragment broken-shader-1.8.0/shaders/glsl/renderchunk.fragment
--- bedrock-vanilla-1.8.0/shaders/glsl/renderchunk.fragment	2018-12-17 21:25:12.000000000 +0900
+++ broken-shader-1.8.0/shaders/glsl/renderchunk.fragment	2018-12-21 14:47:20.000000000 +0900
@@ -26,6 +26,11 @@
 varying vec4 fogColor;
 #endif
 
+// Adding a single "varying" variable somehow breaks the shader.
+#ifndef BYPASS_PIXEL_SHADER
+varying vec4 theProblem;
+#endif
+
 #include "uniformShaderConstants.h"
 #include "util.h"
 
@@ -62,6 +67,9 @@
 	
 vec4 inColor = color;
 
+	// Use the variable to prevent it from being optimized out.
+	inColor = theProblem;
+
 #if defined(BLEND)
 	diffuse.a *= inColor.a;
 #endif
diff -ru bedrock-vanilla-1.8.0/shaders/glsl/renderchunk.vertex broken-shader-1.8.0/shaders/glsl/renderchunk.vertex
--- bedrock-vanilla-1.8.0/shaders/glsl/renderchunk.vertex	2018-12-17 21:25:12.000000000 +0900
+++ broken-shader-1.8.0/shaders/glsl/renderchunk.vertex	2018-12-21 14:46:58.000000000 +0900
@@ -22,6 +22,11 @@
 	varying vec4 fogColor;
 #endif
 
+// Adding a single "varying" variable somehow breaks the shader.
+#ifndef BYPASS_PIXEL_SHADER
+varying vec4 theProblem;
+#endif
+
 #include "uniformWorldConstants.h"
 #include "uniformPerFrameConstants.h"
 #include "uniformShaderConstants.h"
@@ -113,5 +118,8 @@
 		// If the FOG_COLOR isn't used, the reflection on NVN fails to compute the correct size of the constant buffer as the uniform will also be gone from the reflection data
 		color.rgb += FOG_COLOR.rgb * 0.000001;
 	#endif
+
+	// Use the variable to prevent it from being optimized out.
+	theProblem = color;
 #endif
 }