With the move to conduit, we can no longer support GHC 6.12. conduit relies on the mask function, which was introduced with GHC 7. We could actually work around this in conduit and allow it to continue working with GHC 6.12, but frankly, I think it's time to deprecate support anyway.
So if anyone runs into a GHC 6.12 hack for the QQ syntax, just go ahead and remove it.
Remove some QQ hacks #288
If we find any more examples of this, let's clean them up. For now, I think we've found the major examples.