Skip to content

GitLab

  • Menu
Projects Groups Snippets
    • Loading...
  • Help
    • Help
    • Support
    • Community forum
    • Submit feedback
  • Sign in / Register
  • GHC GHC
  • Project information
    • Project information
    • Activity
    • Labels
    • Members
  • Repository
    • Repository
    • Files
    • Commits
    • Branches
    • Tags
    • Contributors
    • Graph
    • Compare
    • Locked Files
  • Issues 4,842
    • Issues 4,842
    • List
    • Boards
    • Service Desk
    • Milestones
    • Iterations
  • Merge requests 456
    • Merge requests 456
  • CI/CD
    • CI/CD
    • Pipelines
    • Jobs
    • Schedules
    • Test Cases
  • Deployments
    • Deployments
    • Releases
  • Analytics
    • Analytics
    • CI/CD
    • Code review
    • Insights
    • Issue
    • Repository
    • Value stream
  • Wiki
    • Wiki
  • Snippets
    • Snippets
  • Activity
  • Graph
  • Create a new issue
  • Jobs
  • Commits
  • Issue Boards
Collapse sidebar
  • Glasgow Haskell Compiler
  • GHCGHC
  • Issues
  • #6152

Closed
Open
Created Jun 08, 2012 by Hiromi Ishii@konnReporter

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
To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information
Assignee
Assign to
Time tracking