we were trying to reify a typeclass, which had a ConstraintKind and we hit upon this error: "Can't represent irreducible predicates in Template Haskell:".

It seems that there is already a ghc bug [ https://ghc.haskell.org/trac/ghc/ticket/7021 ] filed and its status is set as fixed, but there is a comment at the bottom in which the reviewer recommends against merging immediately. Does anybody know when it would get merged in? 
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Yours truly,
Sreenidhi Nair