Re: [GHC] #16095: Infinite loop during error reporting (ignores SIGINT/SIGTERM, then OOMs)

26 Dec 2018

      #16095: Infinite loop during error reporting (ignores SIGINT/SIGTERM, then OOMs)
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        Reporter:  _deepfire         |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.6.1
      Resolution:                    |             Keywords:
Operating System:  Linux             |         Architecture:
 Type of failure:  Compile-time      |  Unknown/Multiple
  crash or panic                     |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by _deepfire):

 Another, different repro for what seems to be a related problem:
 {{{#!hs
 {-# LANGUAGE AllowAmbiguousTypes #-}
 {-# LANGUAGE DataKinds #-}
 {-# LANGUAGE GADTs #-}
 {-# LANGUAGE KindSignatures #-}
 {-# LANGUAGE ScopedTypeVariables #-}
 {-# LANGUAGE TypeApplications #-}
 {-# LANGUAGE TypeOperators #-}
 module Repro
 where

 import           Generics.SOP

 recover :: forall a xs.
            (Code a ~ '[xs], HasDatatypeInfo a)
         => a
 recover =
   case datatypeInfo (Proxy @a) :: DatatypeInfo '[xs] of
     Newtype _ _ _ ->
       let sop :: NP [] xs =
             (undefined
               :: forall c xs
               .  All c xs
               => NP [] xs)
       in undefined
 }}}
 ..once again, dependent on `generics-sop`.

-- 
Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/16095#comment:4
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