[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       |           Version:  8.6.3
  Haskell                            |
           Keywords:                 |  Operating System:  Windows
       Architecture:  x86            |   Type of failure:  Compile-time
                                     |  crash or panic
          Test Case:                 |        Blocked By:
           Blocking:                 |   Related Tickets:
Differential Rev(s):                 |         Wiki Page:
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 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.

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