Bad import not exported [GHC-61689]

This error is triggered when importing a symbol that the module does not export.

Examples

Importing an unexported symbol.

Message

SymbolNotExported.hs:3:16: error: [GHC-61689]
    Module ‘A’ does not export ‘two’.
  |
3 | import A (one, two)
  |                ^^^

Explanation

The module SymbolNotExported imports the symbol two even though A does not export it.

The fix is to remove the bad import.

A.hs

Before

module A (one) where

one :: ()
one = ()

two :: ()
two = ()

After

module A (one) where

one :: ()
one = ()

two :: ()
two = ()

SymbolNotExported.hs

Before

module SymbolNotExported where

import A (one, two)

After

module SymbolNotExported where

import A (one)

Importing a field selector that has been disabled with NoFieldSelectors.

Message

NoFieldSelectors.hs:3:24: error: [GHC-61689]
    Module ‘A’ does not export ‘fint’.
    Suggested fix:
      Notice that ‘fint’ is a field selector belonging to the type ‘A.Foo’
      that has been suppressed by NoFieldSelectors.
  |
3 | import A (Foo (MkFoo), fint)
  |                        ^^^^

Explanation

With FieldSelectors (the default), field selectors are exported such that the following two imports are equivalent:


import A (Foo (MkFoo, fint))
import A (Foo (MkFoo), fint)

With NoFieldSelectors at the definition site (A.hs), the second example is always an error:

import A (Foo (MkFoo), fint)

The fix is to move the selector import to the type or remove it altogether.

A.hs

Before

{-# LANGUAGE NoFieldSelectors #-}

module A (Foo (..)) where

data Foo = MkFoo { fint :: Int, fchar :: Char }

After

{-# LANGUAGE NoFieldSelectors #-}

module A (Foo (..)) where

data Foo = MkFoo { fint :: Int, fchar :: Char }

NoFieldSelectors.hs

Before

module NoFieldSelectors where

import A (Foo (MkFoo), fint)

After

module NoFieldSelectors where

import A (Foo (MkFoo, fint))