This makes sure that we catch all leftover instances of using SYB to do generic operations that we should be using Polyplate for instead. Most modules should only import Data, and possibly Typeable.
This used to work by adding a magic prefix to the error message, but it appears
that doesn't work with the GHC 6.6 version of Parsec. It now searches for a
magic substring anywhere in the error message.
It uses // as a delimeter rather than \0 now, since including nulls in Strings
causes problems -- for example, putStr "a\0b" will only print "a".
