diff --git a/src/com/homelinux/holtrop/opengltest/MyRenderer.java b/src/com/homelinux/holtrop/opengltest/MyRenderer.java
index aa72d4a..2d3e495 100644
--- a/src/com/homelinux/holtrop/opengltest/MyRenderer.java
+++ b/src/com/homelinux/holtrop/opengltest/MyRenderer.java
@@ -6,12 +6,24 @@ import javax.microedition.khronos.opengles.GL10;
 import javax.microedition.khronos.egl.EGLConfig;
 import java.nio.ByteBuffer;
 import java.nio.FloatBuffer;
+import java.nio.IntBuffer;
 import java.nio.ByteOrder;
+import android.util.Log;
 
 public class MyRenderer implements GLSurfaceView.Renderer
 {
     private int m_quad_attrib_buffer;
     private int m_program;
+    private final String DBGTAG = "JoshsOpenGL";
+
+    public void checkGLError(String glOperation)
+    {
+        int error;
+        while ((error = GLES20.glGetError()) != GLES20.GL_NO_ERROR)
+        {
+            Log.e(DBGTAG, glOperation + ": glError " + error);
+        }
+    }
 
     private int load_shader(int type, String source)
     {
@@ -20,6 +32,14 @@ public class MyRenderer implements GLSurfaceView.Renderer
         GLES20.glShaderSource(shader, source);
         GLES20.glCompileShader(shader);
 
+        IntBuffer ib = IntBuffer.allocate(1);
+        GLES20.glGetShaderiv(shader, GLES20.GL_COMPILE_STATUS, ib);
+        if (ib.get(0) != 1)
+        {
+            String info_log = GLES20.glGetShaderInfoLog(shader);
+            Log.e(DBGTAG, "Error compiling shader: " + info_log);
+        }
+
         return shader;
     }
 
@@ -31,6 +51,7 @@ public class MyRenderer implements GLSurfaceView.Renderer
             -1, -1, 0,  0, 1, 0,
             1, -1, 0,   0, 0, 1
         };
+        checkGLError("onSurfaceCreated");
         ByteBuffer bb = ByteBuffer.allocateDirect(attribs.length * 4);
         bb.order(ByteOrder.nativeOrder());
         FloatBuffer fb = bb.asFloatBuffer();
@@ -38,6 +59,7 @@ public class MyRenderer implements GLSurfaceView.Renderer
         fb.position(0);
         int[] buffers = {0};
         GLES20.glGenBuffers(1, buffers, 0);
+        checkGLError("glGenBuffers");
         m_quad_attrib_buffer = buffers[0];
         GLES20.glBindBuffer(GLES20.GL_ARRAY_BUFFER, m_quad_attrib_buffer);
         GLES20.glBufferData(GLES20.GL_ARRAY_BUFFER, 0, fb,
@@ -62,6 +84,14 @@ public class MyRenderer implements GLSurfaceView.Renderer
         GLES20.glAttachShader(m_program, v_shader);
         GLES20.glAttachShader(m_program, f_shader);
         GLES20.glLinkProgram(m_program);
+        checkGLError("glLinkProgram");
+        IntBuffer ib = IntBuffer.allocate(1);
+        GLES20.glGetProgramiv(m_program, GLES20.GL_LINK_STATUS, ib);
+        if (ib.get(0) != 1)
+        {
+            String info_log = GLES20.glGetProgramInfoLog(m_program);
+            Log.e(DBGTAG, "Program log: " + info_log);
+        }
 
         GLES20.glClearColor(1.0f, 0.6f, 0.1f, 1.0f);
     }
@@ -72,17 +102,22 @@ public class MyRenderer implements GLSurfaceView.Renderer
 
         GLES20.glUseProgram(m_program);
         GLES20.glBindBuffer(GLES20.GL_ARRAY_BUFFER, m_quad_attrib_buffer);
+        checkGLError("glBindBuffer");
         int attr_pos = GLES20.glGetAttribLocation(m_program, "pos");
         int attr_color = GLES20.glGetAttribLocation(m_program, "color");
         GLES20.glEnableVertexAttribArray(attr_pos);
         GLES20.glEnableVertexAttribArray(attr_color);
+        checkGLError("glEnableVertexAttribArray");
         GLES20.glVertexAttribPointer(attr_pos, 3, GLES20.GL_FLOAT, false,
                 6 * 4, 0);
         GLES20.glVertexAttribPointer(attr_color, 3, GLES20.GL_FLOAT, false,
                 6 * 4, 3 * 4);
+        checkGLError("glVertexAttribPointer");
         GLES20.glDrawArrays(GLES20.GL_TRIANGLE_FAN, 0, 4);
+        checkGLError("glDrawArrays");
         GLES20.glDisableVertexAttribArray(attr_pos);
         GLES20.glDisableVertexAttribArray(attr_color);
+        checkGLError("glDisableVertexAttribArray");
     }
 
     public void onSurfaceChanged(GL10 unused, int width, int height)