[GHC] #16127: Panic: piResultTys1 in compiler/types/Type.hs:1022:5
#16127: Panic: piResultTys1 in compiler/types/Type.hs:1022:5 -------------------------------------+------------------------------------- Reporter: _deepfire | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.6.1 (Type checker) | Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: Compile-time Unknown/Multiple | crash or panic Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- I apologize in advance for a non-minimised repro. The panic (with a small `-ddump-tc-trace` excerpt, but full log also attached): {{{ tcPolyExprNC Check{Vocab * (k_a4TNy[tau:2] -> Constraint) i_a4TNv[tau:2] (Present * k_a4TNy[tau:2] i_a4TNv[tau:2])} tcSkolemise tcInferId voc_a4TB2 :: Vocab i_a4TMf[sk:1] (Present * * i_a4TMf[sk:1]) tcCheckId voc_a4TB2 Vocab i_a4TMf[sk:1] (Present * * i_a4TMf[sk:1]) Check{Vocab * (k_a4TNy[tau:2] -> Constraint) i_a4TNv[tau:2] (Present * k_a4TNy[tau:2] i_a4TNv[tau:2])} tcWrapResult Actual: Vocab i_a4TMf[sk:1] (Present * * i_a4TMf[sk:1]) Expected: Check{Vocab * (k_a4TNy[tau:2] -> Constraint) i_a4TNv[tau:2] (Present * k_a4TNy[tau:2] i_a4TNv[tau:2])} tc_sub_type_ds ty_actual = Vocab i_a4TMf[sk:1] (Present * * i_a4TMf[sk:1]) ty_expected = Vocab * (k_a4TNy[tau:2] -> Constraint) i_a4TNv[tau:2] (Present * k_a4TNy[tau:2] i_a4TNv[tau:2]) deeply_instantiate final subst origin: arising from a use of ‘voc_a4TB2’ type: Vocab i_a4TMf[sk:1] (Present * * i_a4TMf[sk:1]) new type: Vocab i_a4TMf[sk:1] (Present * * i_a4TMf[sk:1]) subst: [TCvSubst In scope: InScope {i_a4TMf} Type env: [] Co env: []] u_tys tclvl 2 Vocab i_a4TMf[sk:1] (Present * * i_a4TMf[sk:1]) ~ Vocab * (k_a4TNy[tau:2] -> Constraint) i_a4TNv[tau:2] (Present * k_a4TNy[tau:2] i_a4TNv[tau:2]) arising from a type equality Vocab i_a4TMf[sk:1] (Present * * i_a4TMf[sk:1]) ~ Vocab * (k_a4TNy[tau:2] -> Constraint) i_a4TNv[tau:2] (Present * k_a4TNy[tau:2] i_a4TNv[tau:2]) <no location info>: error: ghc: panic! (the 'impossible' happened) (GHC version 8.6.1 for x86_64-unknown-linux): piResultTys1 * [i_a4TNv[tau:2], Present * k_a4TNy[tau:2] i_a4TNv[tau:2]] Call stack: CallStack (from HasCallStack): callStackDoc, called at compiler/utils/Outputable.hs:1160:37 in ghc:Outputable pprPanic, called at compiler/types/Type.hs:1022:5 in ghc:Type Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug }}} Repro (requires Nix & some download time, provides hard repro guarantees in return): {{{ $ git clone https://github.com/deepfire/holotype $ cd holotype $ git reset --hard 7e9f5099eea2080f57205267291eeec50ae4b68a $ nix-shell [nix-shell:~/holotype]$ make }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/16127 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#16127: Panic: piResultTys1 in compiler/types/Type.hs:1022:5 -------------------------------------+------------------------------------- Reporter: _deepfire | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (Type | Version: 8.6.1 checker) | Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple crash or panic | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by _deepfire): * Attachment "ghc.out.xz" added. Repro output -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/16127 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#16127: Panic: piResultTys1 in compiler/types/Type.hs:1022:5 -------------------------------------+------------------------------------- Reporter: _deepfire | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (Type | Version: 8.6.1 checker) | Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple crash or panic | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Description changed by _deepfire: Old description:
I apologize in advance for a non-minimised repro.
The panic (with a small `-ddump-tc-trace` excerpt, but full log also attached):
{{{ tcPolyExprNC Check{Vocab * (k_a4TNy[tau:2] -> Constraint) i_a4TNv[tau:2] (Present * k_a4TNy[tau:2] i_a4TNv[tau:2])} tcSkolemise tcInferId voc_a4TB2 :: Vocab i_a4TMf[sk:1] (Present * * i_a4TMf[sk:1]) tcCheckId voc_a4TB2 Vocab i_a4TMf[sk:1] (Present * * i_a4TMf[sk:1]) Check{Vocab * (k_a4TNy[tau:2] -> Constraint) i_a4TNv[tau:2] (Present * k_a4TNy[tau:2] i_a4TNv[tau:2])} tcWrapResult Actual: Vocab i_a4TMf[sk:1] (Present * * i_a4TMf[sk:1]) Expected: Check{Vocab * (k_a4TNy[tau:2] -> Constraint) i_a4TNv[tau:2] (Present * k_a4TNy[tau:2] i_a4TNv[tau:2])} tc_sub_type_ds ty_actual = Vocab i_a4TMf[sk:1] (Present * * i_a4TMf[sk:1]) ty_expected = Vocab * (k_a4TNy[tau:2] -> Constraint) i_a4TNv[tau:2] (Present * k_a4TNy[tau:2] i_a4TNv[tau:2]) deeply_instantiate final subst origin: arising from a use of ‘voc_a4TB2’ type: Vocab i_a4TMf[sk:1] (Present * * i_a4TMf[sk:1]) new type: Vocab i_a4TMf[sk:1] (Present * * i_a4TMf[sk:1]) subst: [TCvSubst In scope: InScope {i_a4TMf} Type env: [] Co env: []] u_tys tclvl 2 Vocab i_a4TMf[sk:1] (Present * * i_a4TMf[sk:1]) ~ Vocab * (k_a4TNy[tau:2] -> Constraint) i_a4TNv[tau:2] (Present * k_a4TNy[tau:2] i_a4TNv[tau:2]) arising from a type equality Vocab i_a4TMf[sk:1] (Present * * i_a4TMf[sk:1]) ~ Vocab * (k_a4TNy[tau:2] -> Constraint) i_a4TNv[tau:2] (Present * k_a4TNy[tau:2] i_a4TNv[tau:2])
<no location info>: error: ghc: panic! (the 'impossible' happened) (GHC version 8.6.1 for x86_64-unknown-linux): piResultTys1 * [i_a4TNv[tau:2], Present * k_a4TNy[tau:2] i_a4TNv[tau:2]] Call stack: CallStack (from HasCallStack): callStackDoc, called at compiler/utils/Outputable.hs:1160:37 in ghc:Outputable pprPanic, called at compiler/types/Type.hs:1022:5 in ghc:Type
Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug }}}
Repro (requires Nix & some download time, provides hard repro guarantees in return):
{{{ $ git clone https://github.com/deepfire/holotype $ cd holotype $ git reset --hard 7e9f5099eea2080f57205267291eeec50ae4b68a $ nix-shell [nix-shell:~/holotype]$ make }}}
New description: I apologize in advance for a non-minimised repro. The panic (with a small `-ddump-tc-trace` excerpt, but full log also attached -- https://ghc.haskell.org/trac/ghc/attachment/ticket/16127/ghc.out.xz): {{{ tcPolyExprNC Check{Vocab * (k_a4TNy[tau:2] -> Constraint) i_a4TNv[tau:2] (Present * k_a4TNy[tau:2] i_a4TNv[tau:2])} tcSkolemise tcInferId voc_a4TB2 :: Vocab i_a4TMf[sk:1] (Present * * i_a4TMf[sk:1]) tcCheckId voc_a4TB2 Vocab i_a4TMf[sk:1] (Present * * i_a4TMf[sk:1]) Check{Vocab * (k_a4TNy[tau:2] -> Constraint) i_a4TNv[tau:2] (Present * k_a4TNy[tau:2] i_a4TNv[tau:2])} tcWrapResult Actual: Vocab i_a4TMf[sk:1] (Present * * i_a4TMf[sk:1]) Expected: Check{Vocab * (k_a4TNy[tau:2] -> Constraint) i_a4TNv[tau:2] (Present * k_a4TNy[tau:2] i_a4TNv[tau:2])} tc_sub_type_ds ty_actual = Vocab i_a4TMf[sk:1] (Present * * i_a4TMf[sk:1]) ty_expected = Vocab * (k_a4TNy[tau:2] -> Constraint) i_a4TNv[tau:2] (Present * k_a4TNy[tau:2] i_a4TNv[tau:2]) deeply_instantiate final subst origin: arising from a use of ‘voc_a4TB2’ type: Vocab i_a4TMf[sk:1] (Present * * i_a4TMf[sk:1]) new type: Vocab i_a4TMf[sk:1] (Present * * i_a4TMf[sk:1]) subst: [TCvSubst In scope: InScope {i_a4TMf} Type env: [] Co env: []] u_tys tclvl 2 Vocab i_a4TMf[sk:1] (Present * * i_a4TMf[sk:1]) ~ Vocab * (k_a4TNy[tau:2] -> Constraint) i_a4TNv[tau:2] (Present * k_a4TNy[tau:2] i_a4TNv[tau:2]) arising from a type equality Vocab i_a4TMf[sk:1] (Present * * i_a4TMf[sk:1]) ~ Vocab * (k_a4TNy[tau:2] -> Constraint) i_a4TNv[tau:2] (Present * k_a4TNy[tau:2] i_a4TNv[tau:2]) <no location info>: error: ghc: panic! (the 'impossible' happened) (GHC version 8.6.1 for x86_64-unknown-linux): piResultTys1 * [i_a4TNv[tau:2], Present * k_a4TNy[tau:2] i_a4TNv[tau:2]] Call stack: CallStack (from HasCallStack): callStackDoc, called at compiler/utils/Outputable.hs:1160:37 in ghc:Outputable pprPanic, called at compiler/types/Type.hs:1022:5 in ghc:Type Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug }}} Repro (requires Nix & some download time, provides hard repro guarantees in return): {{{ $ git clone https://github.com/deepfire/holotype $ cd holotype $ git reset --hard 7e9f5099eea2080f57205267291eeec50ae4b68a $ nix-shell [nix-shell:~/holotype]$ make }}} -- -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/16127#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#16127: Panic: piResultTys1 in compiler/types/Type.hs:1022:5 -------------------------------------+------------------------------------- Reporter: _deepfire | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (Type | Version: 8.6.1 checker) | Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple crash or panic | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Description changed by _deepfire: Old description:
I apologize in advance for a non-minimised repro.
The panic (with a small `-ddump-tc-trace` excerpt, but full log also attached -- https://ghc.haskell.org/trac/ghc/attachment/ticket/16127/ghc.out.xz):
{{{ tcPolyExprNC Check{Vocab * (k_a4TNy[tau:2] -> Constraint) i_a4TNv[tau:2] (Present * k_a4TNy[tau:2] i_a4TNv[tau:2])} tcSkolemise tcInferId voc_a4TB2 :: Vocab i_a4TMf[sk:1] (Present * * i_a4TMf[sk:1]) tcCheckId voc_a4TB2 Vocab i_a4TMf[sk:1] (Present * * i_a4TMf[sk:1]) Check{Vocab * (k_a4TNy[tau:2] -> Constraint) i_a4TNv[tau:2] (Present * k_a4TNy[tau:2] i_a4TNv[tau:2])} tcWrapResult Actual: Vocab i_a4TMf[sk:1] (Present * * i_a4TMf[sk:1]) Expected: Check{Vocab * (k_a4TNy[tau:2] -> Constraint) i_a4TNv[tau:2] (Present * k_a4TNy[tau:2] i_a4TNv[tau:2])} tc_sub_type_ds ty_actual = Vocab i_a4TMf[sk:1] (Present * * i_a4TMf[sk:1]) ty_expected = Vocab * (k_a4TNy[tau:2] -> Constraint) i_a4TNv[tau:2] (Present * k_a4TNy[tau:2] i_a4TNv[tau:2]) deeply_instantiate final subst origin: arising from a use of ‘voc_a4TB2’ type: Vocab i_a4TMf[sk:1] (Present * * i_a4TMf[sk:1]) new type: Vocab i_a4TMf[sk:1] (Present * * i_a4TMf[sk:1]) subst: [TCvSubst In scope: InScope {i_a4TMf} Type env: [] Co env: []] u_tys tclvl 2 Vocab i_a4TMf[sk:1] (Present * * i_a4TMf[sk:1]) ~ Vocab * (k_a4TNy[tau:2] -> Constraint) i_a4TNv[tau:2] (Present * k_a4TNy[tau:2] i_a4TNv[tau:2]) arising from a type equality Vocab i_a4TMf[sk:1] (Present * * i_a4TMf[sk:1]) ~ Vocab * (k_a4TNy[tau:2] -> Constraint) i_a4TNv[tau:2] (Present * k_a4TNy[tau:2] i_a4TNv[tau:2])
<no location info>: error: ghc: panic! (the 'impossible' happened) (GHC version 8.6.1 for x86_64-unknown-linux): piResultTys1 * [i_a4TNv[tau:2], Present * k_a4TNy[tau:2] i_a4TNv[tau:2]] Call stack: CallStack (from HasCallStack): callStackDoc, called at compiler/utils/Outputable.hs:1160:37 in ghc:Outputable pprPanic, called at compiler/types/Type.hs:1022:5 in ghc:Type
Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug }}}
Repro (requires Nix & some download time, provides hard repro guarantees in return):
{{{ $ git clone https://github.com/deepfire/holotype $ cd holotype $ git reset --hard 7e9f5099eea2080f57205267291eeec50ae4b68a $ nix-shell [nix-shell:~/holotype]$ make }}}
New description: I apologize in advance for a non-minimised repro. The panic (with a small `-ddump-tc-trace` excerpt, but full log also attached): {{{ tcPolyExprNC Check{Vocab * (k_a4TNy[tau:2] -> Constraint) i_a4TNv[tau:2] (Present * k_a4TNy[tau:2] i_a4TNv[tau:2])} tcSkolemise tcInferId voc_a4TB2 :: Vocab i_a4TMf[sk:1] (Present * * i_a4TMf[sk:1]) tcCheckId voc_a4TB2 Vocab i_a4TMf[sk:1] (Present * * i_a4TMf[sk:1]) Check{Vocab * (k_a4TNy[tau:2] -> Constraint) i_a4TNv[tau:2] (Present * k_a4TNy[tau:2] i_a4TNv[tau:2])} tcWrapResult Actual: Vocab i_a4TMf[sk:1] (Present * * i_a4TMf[sk:1]) Expected: Check{Vocab * (k_a4TNy[tau:2] -> Constraint) i_a4TNv[tau:2] (Present * k_a4TNy[tau:2] i_a4TNv[tau:2])} tc_sub_type_ds ty_actual = Vocab i_a4TMf[sk:1] (Present * * i_a4TMf[sk:1]) ty_expected = Vocab * (k_a4TNy[tau:2] -> Constraint) i_a4TNv[tau:2] (Present * k_a4TNy[tau:2] i_a4TNv[tau:2]) deeply_instantiate final subst origin: arising from a use of ‘voc_a4TB2’ type: Vocab i_a4TMf[sk:1] (Present * * i_a4TMf[sk:1]) new type: Vocab i_a4TMf[sk:1] (Present * * i_a4TMf[sk:1]) subst: [TCvSubst In scope: InScope {i_a4TMf} Type env: [] Co env: []] u_tys tclvl 2 Vocab i_a4TMf[sk:1] (Present * * i_a4TMf[sk:1]) ~ Vocab * (k_a4TNy[tau:2] -> Constraint) i_a4TNv[tau:2] (Present * k_a4TNy[tau:2] i_a4TNv[tau:2]) arising from a type equality Vocab i_a4TMf[sk:1] (Present * * i_a4TMf[sk:1]) ~ Vocab * (k_a4TNy[tau:2] -> Constraint) i_a4TNv[tau:2] (Present * k_a4TNy[tau:2] i_a4TNv[tau:2]) <no location info>: error: ghc: panic! (the 'impossible' happened) (GHC version 8.6.1 for x86_64-unknown-linux): piResultTys1 * [i_a4TNv[tau:2], Present * k_a4TNy[tau:2] i_a4TNv[tau:2]] Call stack: CallStack (from HasCallStack): callStackDoc, called at compiler/utils/Outputable.hs:1160:37 in ghc:Outputable pprPanic, called at compiler/types/Type.hs:1022:5 in ghc:Type Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug }}} Repro (requires Nix & some download time, provides hard repro guarantees in return): {{{ $ git clone https://github.com/deepfire/holotype $ cd holotype $ git reset --hard 7e9f5099eea2080f57205267291eeec50ae4b68a $ nix-shell [nix-shell:~/holotype]$ cabal build lib:holotype }}} -- -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/16127#comment:2 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#16127: Panic: piResultTys1 in compiler/types/Type.hs:1022:5 -------------------------------------+------------------------------------- Reporter: _deepfire | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (Type | Version: 8.6.1 checker) | Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple crash or panic | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by _deepfire): ..and the following is what hints at the cause (kind polymoprhism mismatch between `.hs` and `.hs-boot`): {{{ $ git diff HEAD~1.. diff --git a/src/Holo/Widget2.hs-boot b/src/Holo/Widget2.hs-boot index d63c757..13ed889 100644 --- a/src/Holo/Widget2.hs-boot +++ b/src/Holo/Widget2.hs-boot @@ -3,6 +3,7 @@ where import Data.Kind (Type) import qualified Data.TypeMap.Dynamic as TM +import GHC.Types (Constraint) import Generics.SOP (Top) import Generics.SOP.Monadic (Result) import Reflex (Dynamic) @@ -15,7 +16,7 @@ import {-# SOURCE #-} data Definition i a -newtype Vocab i c = Vocab (TM.TypeMap (HoloTag i)) +newtype Vocab (i ∷ Type) (c ∷ Type → Constraint) = Vocab (TM.TypeMap (HoloTag i)) data HoloTag i type Blank i = Item Top PBlank }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/16127#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#16127: Panic: piResultTys1 in compiler/types/Type.hs:1022:5 -------------------------------------+------------------------------------- Reporter: _deepfire | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (Type | Version: 8.6.1 checker) | Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple crash or panic | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by _deepfire): Commit `b87f5bf56e75042e4a55b5b806f6ff24021ea040` on the `ghc-16127-repros` branch of the `holotype` repository partially minimises the involved modules. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/16127#comment:4 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#16127: Panic: piResultTys1 in compiler/types/Type.hs:1022:5 -------------------------------------+------------------------------------- Reporter: _deepfire | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (Type | Version: 8.6.1 checker) | Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple crash or panic | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by RyanGlScott): Alas, I can't follow the directions to reproduce this, as it fails quite early for me: {{{ $ nix-shell unpacking 'https://github.com/NixOS/nixpkgs/archive/cd68a8c7cc602e75a4abbadc94663347a73...'... error: undefined variable 'stdenv' at /home/rgscott/Documents/Hacking/Haskell/holotype/manual- overrides.nix:24:15 (use '--show-trace' to show detailed location information) }}} If you could produce a reproducible example without the steep requirement to install Nix or `reflex`, that would be greatly helpful. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/16127#comment:5 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#16127: Panic: piResultTys1 in compiler/types/Type.hs:1022:5 -------------------------------------+------------------------------------- Reporter: _deepfire | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (Type | Version: 8.6.1 checker) | Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple crash or panic | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Old description:
I apologize in advance for a non-minimised repro.
The panic (with a small `-ddump-tc-trace` excerpt, but full log also attached):
{{{ tcPolyExprNC Check{Vocab * (k_a4TNy[tau:2] -> Constraint) i_a4TNv[tau:2] (Present * k_a4TNy[tau:2] i_a4TNv[tau:2])} tcSkolemise tcInferId voc_a4TB2 :: Vocab i_a4TMf[sk:1] (Present * * i_a4TMf[sk:1]) tcCheckId voc_a4TB2 Vocab i_a4TMf[sk:1] (Present * * i_a4TMf[sk:1]) Check{Vocab * (k_a4TNy[tau:2] -> Constraint) i_a4TNv[tau:2] (Present * k_a4TNy[tau:2] i_a4TNv[tau:2])} tcWrapResult Actual: Vocab i_a4TMf[sk:1] (Present * * i_a4TMf[sk:1]) Expected: Check{Vocab * (k_a4TNy[tau:2] -> Constraint) i_a4TNv[tau:2] (Present * k_a4TNy[tau:2] i_a4TNv[tau:2])} tc_sub_type_ds ty_actual = Vocab i_a4TMf[sk:1] (Present * * i_a4TMf[sk:1]) ty_expected = Vocab * (k_a4TNy[tau:2] -> Constraint) i_a4TNv[tau:2] (Present * k_a4TNy[tau:2] i_a4TNv[tau:2]) deeply_instantiate final subst origin: arising from a use of ‘voc_a4TB2’ type: Vocab i_a4TMf[sk:1] (Present * * i_a4TMf[sk:1]) new type: Vocab i_a4TMf[sk:1] (Present * * i_a4TMf[sk:1]) subst: [TCvSubst In scope: InScope {i_a4TMf} Type env: [] Co env: []] u_tys tclvl 2 Vocab i_a4TMf[sk:1] (Present * * i_a4TMf[sk:1]) ~ Vocab * (k_a4TNy[tau:2] -> Constraint) i_a4TNv[tau:2] (Present * k_a4TNy[tau:2] i_a4TNv[tau:2]) arising from a type equality Vocab i_a4TMf[sk:1] (Present * * i_a4TMf[sk:1]) ~ Vocab * (k_a4TNy[tau:2] -> Constraint) i_a4TNv[tau:2] (Present * k_a4TNy[tau:2] i_a4TNv[tau:2])
<no location info>: error: ghc: panic! (the 'impossible' happened) (GHC version 8.6.1 for x86_64-unknown-linux): piResultTys1 * [i_a4TNv[tau:2], Present * k_a4TNy[tau:2] i_a4TNv[tau:2]] Call stack: CallStack (from HasCallStack): callStackDoc, called at compiler/utils/Outputable.hs:1160:37 in ghc:Outputable pprPanic, called at compiler/types/Type.hs:1022:5 in ghc:Type
Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug }}}
Repro (requires Nix & some download time, provides hard repro guarantees in return):
{{{ $ git clone https://github.com/deepfire/holotype $ cd holotype $ git reset --hard 7e9f5099eea2080f57205267291eeec50ae4b68a $ nix-shell [nix-shell:~/holotype]$ cabal build lib:holotype }}}
New description: I apologize in advance for a non-minimised repro. The panic (with a small `-ddump-tc-trace` excerpt, but full log also attached): {{{ tcPolyExprNC Check{Vocab * (k_a4TNy[tau:2] -> Constraint) i_a4TNv[tau:2] (Present * k_a4TNy[tau:2] i_a4TNv[tau:2])} tcSkolemise tcInferId voc_a4TB2 :: Vocab i_a4TMf[sk:1] (Present * * i_a4TMf[sk:1]) tcCheckId voc_a4TB2 Vocab i_a4TMf[sk:1] (Present * * i_a4TMf[sk:1]) Check{Vocab * (k_a4TNy[tau:2] -> Constraint) i_a4TNv[tau:2] (Present * k_a4TNy[tau:2] i_a4TNv[tau:2])} tcWrapResult Actual: Vocab i_a4TMf[sk:1] (Present * * i_a4TMf[sk:1]) Expected: Check{Vocab * (k_a4TNy[tau:2] -> Constraint) i_a4TNv[tau:2] (Present * k_a4TNy[tau:2] i_a4TNv[tau:2])} tc_sub_type_ds ty_actual = Vocab i_a4TMf[sk:1] (Present * * i_a4TMf[sk:1]) ty_expected = Vocab * (k_a4TNy[tau:2] -> Constraint) i_a4TNv[tau:2] (Present * k_a4TNy[tau:2] i_a4TNv[tau:2]) deeply_instantiate final subst origin: arising from a use of ‘voc_a4TB2’ type: Vocab i_a4TMf[sk:1] (Present * * i_a4TMf[sk:1]) new type: Vocab i_a4TMf[sk:1] (Present * * i_a4TMf[sk:1]) subst: [TCvSubst In scope: InScope {i_a4TMf} Type env: [] Co env: []] u_tys tclvl 2 Vocab i_a4TMf[sk:1] (Present * * i_a4TMf[sk:1]) ~ Vocab * (k_a4TNy[tau:2] -> Constraint) i_a4TNv[tau:2] (Present * k_a4TNy[tau:2] i_a4TNv[tau:2]) arising from a type equality Vocab i_a4TMf[sk:1] (Present * * i_a4TMf[sk:1]) ~ Vocab * (k_a4TNy[tau:2] -> Constraint) i_a4TNv[tau:2] (Present * k_a4TNy[tau:2] i_a4TNv[tau:2]) <no location info>: error: ghc: panic! (the 'impossible' happened) (GHC version 8.6.1 for x86_64-unknown-linux): piResultTys1 * [i_a4TNv[tau:2], Present * k_a4TNy[tau:2] i_a4TNv[tau:2]] Call stack: CallStack (from HasCallStack): callStackDoc, called at compiler/utils/Outputable.hs:1160:37 in ghc:Outputable pprPanic, called at compiler/types/Type.hs:1022:5 in ghc:Type Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug }}} Repro (requires Nix & some download time, provides hard repro guarantees in return): {{{ $ git clone https://github.com/deepfire/holotype $ cd holotype $ git reset --hard 5c80e9239a3c18d67106920db8f832abc7bd9a93 $ nix-shell [nix-shell:~/holotype]$ cabal build lib:holotype }}} -- Comment (by _deepfire): Ryan, I apologize for the repro fiasco -- I've reproduced your problem in a different environment and fixed it in commit `5c80e9239a3c18d67106920db8f832abc7bd9a93`. . -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/16127#comment:6 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#16127: Panic: piResultTys1 in compiler/types/Type.hs:1022:5 -------------------------------------+------------------------------------- Reporter: _deepfire | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (Type | Version: 8.6.1 checker) | Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple crash or panic | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by RyanGlScott): This can be minimized down to the following four modules: {{{#!hs -- A.hs module A (Vocab(..)) where import Data.Kind import {-# SOURCE #-} B data T i = MkT i thisPanics :: x thisPanics = method (MkT 'a') }}} {{{#!hs -- A.hs-boot {-# LANGUAGE PolyKinds #-} module A where data T i }}} {{{#!hs -- B.hs module B where import A class C i where method :: T i -> x }}} {{{#!hs -- B.hs-boot module B where import {-# SOURCE #-} A class C i where method :: T i -> x }}} ----- {{{ $ /opt/ghc/8.6.3/bin/ghc A.hs [1 of 4] Compiling A[boot] ( A.hs-boot, A.o-boot ) [2 of 4] Compiling B[boot] ( B.hs-boot, B.o-boot ) [3 of 4] Compiling A ( A.hs, A.o ) ghc: panic! (the 'impossible' happened) (GHC version 8.6.3 for x86_64-unknown-linux): piResultTys1 * [i_aYf[tau:1]] Call stack: CallStack (from HasCallStack): callStackDoc, called at compiler/utils/Outputable.hs:1160:37 in ghc:Outputable pprPanic, called at compiler/types/Type.hs:1022:5 in ghc:Type }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/16127#comment:7 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#16127: Panic: piResultTys1 in compiler/types/Type.hs:1022:5 -------------------------------------+------------------------------------- Reporter: _deepfire | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (Type | Version: 8.6.1 checker) | Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple crash or panic | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by simonpj): I know what is happening. In `A.hs-boot` (which has `-XPolyKinds`) we have {{{ T :: forall k. k -> Type }}} Then in `B.hs-boot` we have {{{ method :: forall i x. C i => T @Type i -> x }}} When compiling `A.hs` (no `-XPolyKinds`) we get {{{ T :: Type -> Type }}} Now, when we deserialise that imported singature for `method` we construct the ill-kinded type `T @Type i`. Result, disaster. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/16127#comment:8 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#16127: Panic: piResultTys1 in compiler/types/Type.hs:1022:5 -------------------------------------+------------------------------------- Reporter: _deepfire | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (Type | Version: 8.6.1 checker) | Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple crash or panic | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by simonpj): What to do? The real problem is that if `A.hs` defines a type `T` differently than `A.hs-boot`, then anything imported into `A` whose type or kind mentions `T` is going to be ill-kinded. So I think the Right Thing is * Immediately after typechecking a type/class declaration `T`, check if there is a hs-boot file definition for it; if so, compare, and fail if there is a mis-match. Currently the hs-boot file comparison happens all at the end, so this would require a little re-plumbing. But before doing that, let's check that everyone agrees. (Now that we know the cause, it should be easy to make an even simpler repro case.) -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/16127#comment:9 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#16127: Panic: piResultTys1 in compiler/types/Type.hs:1022:5 -------------------------------------+------------------------------------- Reporter: _deepfire | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (Type | Version: 8.6.1 checker) | Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple crash or panic | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by goldfire): Could this happen without the `-XPolyKinds` disparity? It sounds like "yes". If that's the case, then I agree with your plan. If the only way this happens is the `-XPolyKinds` disparity, then I would want to think about this other option: Brutally require that an .hs-boot file and its regular-module counterpart have exactly the same set of extensions enabled. This could be checked very early on, halting with an appropriate error message before ever looking at declarations. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/16127#comment:10 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#16127: Panic: piResultTys1 in compiler/types/Type.hs:1022:5 -------------------------------------+------------------------------------- Reporter: _deepfire | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (Type | Version: 8.6.1 checker) | Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple crash or panic | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by simonpj): Yes, I believe it could happens simply if the T in `A.hs-boot` differs from the `T` in `A.hs`; eg differently-kinded arguments. But I have not tried to cause crashes/Lint errors by doing this; that'd be a good thing to try. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/16127#comment:11 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#16127: Panic: piResultTys1 in compiler/types/Type.hs:1022:5 -------------------------------------+------------------------------------- Reporter: _deepfire | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (Type | Version: 8.6.1 checker) | Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple crash or panic | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by goldfire): That's what I thought -- the kind disparity could be brought about in a number of ways. Yes, it seems the only real way to fix this is more eager consistency checking between .hs-boot files and .hs files. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/16127#comment:12 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#16127: Panic: piResultTys1 in compiler/types/Type.hs:1022:5 -------------------------------------+------------------------------------- Reporter: _deepfire | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (Type | Version: 8.6.1 checker) | Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple crash or panic | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by RyanGlScott): For the sake of completeness, here is a variant of the program suite in comment:7 that exhibits the same panic by providing different numbers of arguments to `T` instead of using `PolyKinds`: {{{#!hs -- A.hs module A where import {-# SOURCE #-} B data T i = MkT i thisPanics :: x thisPanics = method (MkT 'a') }}} {{{#!hs -- A.hs-boot module A where data T i1 i2 }}} {{{#!hs -- B.hs module B where import A class C i where method :: T i -> x }}} {{{#!hs -- B.hs-boot module B where import {-# SOURCE #-} A class C i where method :: T i a -> x }}} ----- {{{ $ /opt/ghc/8.6.3/bin/ghc A.hs [1 of 4] Compiling A[boot] ( A.hs-boot, A.o-boot ) [2 of 4] Compiling B[boot] ( B.hs-boot, B.o-boot ) [3 of 4] Compiling A ( A.hs, A.o ) ghc: panic! (the 'impossible' happened) (GHC version 8.6.3 for x86_64-unknown-linux): piResultTys1 * [a_aYd[tau:1]] Call stack: CallStack (from HasCallStack): callStackDoc, called at compiler/utils/Outputable.hs:1160:37 in ghc:Outputable pprPanic, called at compiler/types/Type.hs:1022:5 in ghc:Type }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/16127#comment:13 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#16127: Panic: piResultTys1 in compiler/types/Type.hs:1022:5 -------------------------------------+------------------------------------- Reporter: _deepfire | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (Type | Version: 8.6.1 checker) | Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple crash or panic | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by simonpj): Thanks. I think it should also be easy to provoke with only one one hs- boot file; and with no classes. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/16127#comment:14 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#16127: Panic: piResultTys1 in compiler/types/Type.hs:1022:5 -------------------------------------+------------------------------------- Reporter: _deepfire | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (Type | Version: 8.6.1 checker) | Resolution: | Keywords: hs-boot Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple crash or panic | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by simonpj): * keywords: => hs-boot Comment: I'm snowed under at the moment, but this ticket would not be hard to solve for someone who is wanting to help in typechecker-land. I know what to do, and can advise. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/16127#comment:15 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
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