:info prints kinds in closed type family equations without enabling -fprint-explicit-kinds

Load this file into GHCi:

{-# LANGUAGE PolyKinds #-}
{-# LANGUAGE TypeFamilies #-}
module Bug where

type family Foo (a :: k) :: k where
  Foo a = a

And run :info on Foo:

$ /opt/ghc/8.4.3/bin/ghci Bug.hs
GHCi, version 8.4.3: http://www.haskell.org/ghc/  :? for help
Loaded GHCi configuration from /home/ryanglscott/.ghci
[1 of 1] Compiling Bug              ( Bug.hs, interpreted )
Ok, one module loaded.
λ> :i Foo
type family Foo (a :: k) :: k
  where Foo k a = a
        -- Defined at Bug.hs:5:1

Note that when printing the equation for Foo, the kind k is treated as though it were the first visible argument to Foo, even though -fprint-explicit-kinds is not enabled. This is because ppr_tc_args in IfaceType does not take -fprint-explicit-kinds into account.

Patch incoming (pending a ./validate).

Trac metadata

Trac field	Value
Version	8.4.3
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
Test case
Differential revisions
BlockedBy
Related
Blocking
CC
Operating system
Architecture

changed milestone to %8.6.1

changed weight to 5

added Tbug Trac import labels

Trac metadata

Trac field	Value
Differential revisions	- → D4932

mentioned in commit dbdcacfc

Trac metadata

Trac field	Value
Test case	- → ghci/scripts/T15341

added 1 deleted label

closed

#15341 (closed) merged in 113bdb8b.

Trac metadata

Trac field	Value
Resolution	Unresolved → ResolvedFixed

removed 1 deleted label

added TypeFamilies label

added Pnormal label