Out-of-scope suggestion given for an out-of-scope variable when using TH

With GHC 8.x, compiling

{-# LANGUAGE TemplateHaskell #-}

module A where

import Language.Haskell.TH

sep :: Q [Dec]
sep = [d| x = () |]

and

{-# LANGUAGE TemplateHaskell #-}

module B where

import A

f :: Int
f = foo

$(sep)

foo :: Int
foo = 3

produces

$ ghc-HEAD/inplace/bin/ghc-stage2 --version
The Glorious Glasgow Haskell Compilation System, version 8.1.20160303
$ ghc-HEAD/inplace/bin/ghc-stage2 B.hs
[1 of 2] Compiling A                ( A.hs, A.o )
[2 of 2] Compiling B                ( B.hs, B.o )

B.hs:8:5: error:
    • Variable not in scope: foo :: Int
    • Perhaps you meant ‘foo’ (line 13)

The problem is that when the typechecker constructs the suggestion, it uses the currently available GlobalRdrEnv rather than the one in existence when the renamer determined that foo is unbound.

Trac metadata

Trac field	Value
Version	8.0.1-rc2
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
Test case
Differential revisions
BlockedBy
Related
Blocking
CC
Operating system
Architecture