#15625: GHC panic, with QuantifiedConstraints
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Reporter: Iceland_jack | Owner: (none)
Type: bug | Status: new
Priority: normal | Milestone:
Component: Compiler | Version: 8.6.1-beta1
Resolution: | Keywords:
| QuantifiedConstraints
Operating System: Unknown/Multiple | Architecture:
| Unknown/Multiple
Type of failure: None/Unknown | Test Case:
Blocked By: | Blocking:
Related Tickets: | Differential Rev(s):
Wiki Page: |
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Comment (by RyanGlScott):
If you don't have a GHC build with `ASSERT`ions enabled, then it's worth
noting that this program also triggers a Core Lint error:
{{{
$ /opt/ghc/8.6.1/bin/ghci Bug.hs -dcore-lint
GHCi, version 8.6.0.20180907: http://www.haskell.org/ghc/ :? for help
Loaded GHCi configuration from /home/ryanglscott/.ghci
[1 of 1] Compiling Main ( Bug.hs, interpreted )
*** Core Lint errors : in result of Desugar (after optimization) ***
<no location info>: warning:
[in body of letrec with binders $dIP_a2KT :: HasCallStack]
co_a2Lc :: a_a1Iw[sk:1] ~# 'KL Any
[LclId[CoVarId]] is out of scope
*** Offending Program ***
<elided>
ekki__
:: forall (m :: * -> *) (a :: KL_kind m).
(Monad m, forall xx. AsKL a xx) =>
KLEISLI m a a
[LclIdX]
ekki__
= \ (@ (m_a1Iv :: * -> *))
(@ (a_a1Iw :: KL_kind m_a1Iv))
_ [Occ=Dead]
(df_a1Iz :: forall xx. AsKL a_a1Iw xx) ->
case \ (@ xx_a1Fp) ->
heq_sel
@ (KL_kind m_a1Iv)
@ (KL_kind m_a1Iv)
@ a_a1Iw
@ ('KL xx_a1Fp)
($p1~
@ (KL_kind m_a1Iv)
@ a_a1Iw
@ ('KL xx_a1Fp)
($p1AsKL @ m_a1Iv @ a_a1Iw @ xx_a1Fp (df_a1Iz @
xx_a1Fp)))
of df_a2Lp
{ __DEFAULT ->
let {
$dIP_a2KT :: HasCallStack
[LclId]
$dIP_a2KT
= (pushCallStack
(unpackCString# "undefined"#,
SrcLoc
(unpackCString# "main"#)
(unpackCString# "Main"#)
(unpackCString# "Bug.hs"#)
(I# 16#)
(I# 20#)
(I# 16#)
(I# 29#))
((emptyCallStack
`cast` (Sym (N:IP[0] <"callStack">_N <CallStack>_N)
:: CallStack ~R# (?callStack::CallStack)))
`cast` (N:IP[0] <"callStack">_N <CallStack>_N
:: (?callStack::CallStack) ~R# CallStack)))
`cast` (Sym (N:IP[0] <"callStack">_N <CallStack>_N)
:: CallStack ~R# (?callStack::CallStack)) } in
(break<0>()
$WMkKLEISLI
@ Any
@ m_a1Iv
@ Any
(undefined @ 'LiftedRep @ (Any -> m_a1Iv Any) $dIP_a2KT))
`cast` ((KLEISLI