#14904: Compiler panic (piResultTy) -------------------------------------+------------------------------------- Reporter: kcsongor | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (Type | Version: 8.2.2 checker) | Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: 14873 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by kcsongor): * Attachment "Bug.hs" added. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14904 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#14904: Compiler panic (piResultTy) -------------------------------------+------------------------------------- Reporter: kcsongor | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (Type | Version: 8.2.2 checker) | Resolution: | Keywords: TypeInType Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: #14873 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by RyanGlScott): * related: 14873 => #14873 Comment: It looks like commit faec8d358985e5d0bf363bd96f23fe76c9e281f7 (`Track type variable scope more carefully.`) nabbed this one. After that commit, I get error messages instead of panics on each program in the ticket. For the first program: {{{#!hs {-# LANGUAGE RankNTypes #-} {-# LANGUAGE TypeFamilies #-} {-# LANGUAGE TypeInType #-} module Bug where import Data.Kind type family F (f :: forall a. g a) :: Type where F (f :: forall a. g a) = Int }}} {{{ $ ghc/inplace/bin/ghc-stage2 Bug.hs [1 of 1] Compiling Bug ( Bug.hs, Bug.o ) Bug.hs:8:1: error: You have written a *complete user-suppled kind signature*, but the following variable is undetermined: k0 :: * Perhaps add a kind signature. Inferred kinds of user-written variables: g :: k0 -> * f :: forall (a :: k0). g a | 8 | type family F (f :: forall a. g a) :: Type where | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ }}} For the second program: {{{#!hs {-# LANGUAGE RankNTypes #-} {-# LANGUAGE TypeFamilies #-} {-# LANGUAGE TypeInType #-} module Bug2 where import Data.Kind type family F f :: Type where F ((f :: forall a. g a) :: forall a. g a) = Int }}} {{{ $ ghc/inplace/bin/ghc-stage2 Bug2.hs [1 of 1] Compiling Bug2 ( Bug2.hs, Bug2.o ) Bug2.hs:9:7: error: • Expected kind ‘forall (a :: k1). g a’, but ‘f’ has kind ‘k0’ • In the first argument of ‘F’, namely ‘((f :: forall a. g a) :: forall a. g a)’ In the type family declaration for ‘F’ | 9 | F ((f :: forall a. g a) :: forall a. g a) = Int | ^ }}} I'll add regression tests and close this. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14904#comment:2 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#14904: Compiler panic (piResultTy) -------------------------------------+------------------------------------- Reporter: kcsongor | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (Type | Version: 8.2.2 checker) | Resolution: | Keywords: TypeInType Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: #14873 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by Ryan Scott ): In [changeset:"5de0be8d7ee48eac0af42387eb40b5a5a9b08a35/ghc" 5de0be8/ghc]: {{{ #!CommitTicketReference repository="ghc" revision="5de0be8d7ee48eac0af42387eb40b5a5a9b08a35" Add regression tests for #14904 Trac #14904 was fixed in commit faec8d358985e5d0bf363bd96f23fe76c9e281f7. Let's add some tests to ensure that it stays fixed. }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14904#comment:4 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#14904: Compiler panic (piResultTy) -------------------------------------+------------------------------------- Reporter: kcsongor | Owner: (none) Type: bug | Status: closed Priority: normal | Milestone: 8.6.1 Component: Compiler (Type | Version: 8.2.2 checker) | Resolution: fixed | Keywords: TypeInType Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: | typecheck/should_fail/T14904a, | typecheck/should_fail/T14904b Blocked By: | Blocking: Related Tickets: #14873 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by goldfire): Hooray for RyanGlScott! :) -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14904#comment:6 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#14904: Compiler panic (piResultTy) -------------------------------------+------------------------------------- Reporter: kcsongor | Owner: (none) Type: bug | Status: closed Priority: normal | Milestone: 8.6.1 Component: Compiler (Type | Version: 8.2.2 checker) | Resolution: fixed | Keywords: TypeInType Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: | typecheck/should_fail/T14904a, | typecheck/should_fail/T14904b Blocked By: | Blocking: Related Tickets: #14873 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by Simon Peyton Jones ): In [changeset:"30b029bea9abe1f5f2855d9e7f0ae26a18cf049b/ghc" 30b029be/ghc]: {{{ #!CommitTicketReference repository="ghc" revision="30b029bea9abe1f5f2855d9e7f0ae26a18cf049b" Fix typechecking of kind signatures When typechecking a type like Maybe (a :: <kind-sig>) with a kind signature, we were using tc_lhs_kind to typecheck the signature. But that's utterly wrong; we need the signature to be fully solid (non unresolved equalities) before using it. In the case of Trac #14904 we went on to instantiate the kind signature, when it still had embedded unsolved constraints. This tripped the level-checking assertion when unifying a variable. The fix looks pretty easy to me: just call tcLHsKind instead. I had to add KindSigCtxt to }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14904#comment:8 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#14904: Compiler panic (piResultTy) -------------------------------------+------------------------------------- Reporter: kcsongor | Owner: (none) Type: bug | Status: closed Priority: normal | Milestone: 8.6.1 Component: Compiler (Type | Version: 8.2.2 checker) | Resolution: fixed | Keywords: TypeInType Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: | typecheck/should_fail/T14904a, | typecheck/should_fail/T14904b, | indexed-types/should_fail/T14904 Blocked By: | Blocking: Related Tickets: #14873 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by goldfire): Checked. Looks good, except for the typo fix I pushed. Yes, this was an oversight. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14904#comment:10 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler