Type synonym for Type family + DataKinds won't recompile due to internal error
I have following program:
{-# LANGUAGE DataKinds, TypeFamilies, GADTs #-}
module Main where
data U = Unit
data SU (a :: U) where
SInt :: SU Unit
type family I (a :: U) :: U
type instance I Unit = Unit
type SUI a = SU (I a)
main :: IO ()
main = return ()
This program compiles successfully, but won't recompile due to an internal error.
$ ghc WontCompile.hs
[1 of 1] Compiling Main ( WontCompile.hs, WontCompile.o )
Linking WontCompile ...
$ ghc WontCompile.hs -fforce-recomp
[1 of 1] Compiling Main ( WontCompile.hs, WontCompile.o )
WontCompile.hs:12:18:
GHC internal error: `I' is not in scope during type checking, but it passed the renamer
tcl_env of environment: [(a9O, AThing k_a9X)]
In the type `SU (I a)'
In the type synonym declaration for `SUI'
Trac metadata
Trac field | Value |
---|---|
Version | 7.4.1 |
Type | Bug |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | Compiler |
Test case | |
Differential revisions | |
BlockedBy | |
Related | |
Blocking | |
CC | |
Operating system | |
Architecture |