Template Haskell reify does not return declaration

main.hs

-- $ ghc --version
-- The Glorious Glasgow Haskell Compilation System, version 8.0.1
-- $ runghc main.hs
-- "Nothing"
{-# LANGUAGE TemplateHaskell #-}
import THStuff

-- This definition has a known value.
-- If we reify it, it should have a declaration of "Just 5" (with some extra junk)
value :: Int
value = 5

-- flush so that "value" is available below
return []

main = do
  -- What declaration do we get when we reify?
  -- "Nothing".
  print $(get 'value)

THStuff.hs

-- Template haskell parts need to be in separate module, because of staging restriction.
-- Use GHC 8, since the VarI constructor changed between 7 and 8.
{-# LANGUAGE TemplateHaskell #-}
module THStuff where
import Language.Haskell.TH

-- Try to convert a name into its definition.
-- This would be really useful for forcing definitions to be inlined into a particular callsite.
get :: Name -> Q Exp
get nm = do
  -- Reify here returns an Info. https://hackage.haskell.org/package/template-haskell-2.11.0.0/docs/Language-Haskell-TH.html#t:Info
  -- We only care about the VarI case, which would include names with known values such as function definitions, as well as unknown values like function arguments.
  VarI _ _ dec <- reify nm
  -- The third argument (dec) is a Maybe Dec.
  -- From the docs:
  -- The Maybe Dec field contains Just the declaration which defined the variable -- including the RHS of the declaration -- or else Nothing, in the case where the RHS is unavailable to the compiler. At present, this value is _always_ Nothing: returning the RHS has not yet been implemented because of lack of interest.

  -- Convert the dec into a string just so we can return it.
  let d = show dec
  [|d|]