Re: [GHC] #16057: GHC 8.6.3 hangs with Template Haskell on Windows 10

16 Dec 2018

      #16057: GHC 8.6.3 hangs with Template Haskell on Windows 10
-------------------------------------+-------------------------------------
        Reporter:  gizmo.mk0         |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Template Haskell  |              Version:  8.6.3
      Resolution:                    |             Keywords:
Operating System:  Windows           |         Architecture:  x86
 Type of failure:  Compile-time      |            Test Case:
  crash or panic                     |
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Description changed by gizmo.mk0:

Old description:
...
Have these two files in a directory:
Main.hs:
{{{#!hs
{-# LANGUAGE TemplateHaskell #-}
module Main where
import Helper
main = return ()
test
}}}
Helper.hs:
{{{#!hs
{-# LANGUAGE TemplateHaskell #-}
module Helper where
import Language.Haskell.TH
test :: Q [Dec]
test = return []
}}}
If compiled with `ghc Main.hs`, the compilation freezes, when it reaches
`Main`.
This works well on Linux (Ubuntu 18) using GHC 8.6.3, and there is no
problem in GHC 8.4.3 on either Windows or Linux.
GCC version: 8.2.0 Rev3 (from MSYS2) / 7.2.0 Rev1 (from cmd.exe)
Adding -dcore-lint does not change the outcome.
New description:

 Have these two files in a directory:

 Main.hs:
 {{{#!hs
 {-# LANGUAGE TemplateHaskell #-}
 module Main where
 import Helper

 main = return ()

 test
 }}}

 Helper.hs:
 {{{#!hs
 {-# LANGUAGE TemplateHaskell #-}
 module Helper where
 import Language.Haskell.TH

 test :: Q [Dec]
 test = return []
 }}}

 If compiled with `ghc Main.hs`, the compilation freezes, when it reaches
 `Main`.

 This compiles without problems on Linux (Ubuntu 18) using GHC 8.6.3, and
 there is no problem in GHC 8.4.3 on either Windows or Linux.

 GCC version: 8.2.0 Rev3 (from MSYS2) / 7.2.0 Rev1 (from cmd.exe)

 Adding -dcore-lint does not change the outcome.

--

-- 
Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/16057#comment:1
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