Hit a bug in my ARB buffer texture test-case this morning and decided to try out GLSLDevil to see what's going on in the shader (basically I seem to be getting out the wrong values from my texelFetch() calls).  Long story short, while I can do a bit of hackery to get past some initial failures (basically ctypes utils find_library doesn't use the hooks GLSLDevil is using), it appears that the whole edifice crashes when attempting to load entry points from the wrapper library which are not wrapped (or something of that nature), which happens during PyOpenGL initialization... so basically a bit on the useless side.  So, for now, no advice regarding getting it working properly.