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

[GHC]

#16057: GHC 8.6.3 hangs with Template Haskell on Windows 10
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        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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Comment (by Phyx-):

 Yeah I've started taking a look at it, I can't reproduce it in HEAD nor
 can I with 8.6.2, only 8.6.3.

 Where it ends is an endless loop in

 {{{
 #0 0x0000000003d53506 in interpretBCO (cap=0x4604380 <MainCapability>) at
 rts\Interpreter.c:395
 #1 0x0000000003d588b7 in schedule
 (initialCapability=initialCapability at entry=0x4604380 <MainCapability>,
 task=<optimized out>, task at entry=0x4d6ef00) at rts\Schedule.c:458
 #2 0x0000000003d5914b in scheduleWaitThread (tso=0x7505ba8,
 ret=ret at entry=0x0, pcap=pcap at entry=0x4cdfd18) at rts\Schedule.c:2533
 #3 0x0000000003d50968 in rts_evalLazyIO (cap=cap at entry=0x4cdfd18,
 p=p at entry=0x3d9f0d8 <ZCMain_main_closure>, ret=ret at entry=0x0) at
 rts\RtsAPI.c:530
 #4 0x0000000003d4fc95 in hs_main (argc=<optimized out>, argv=<optimized
 out>, main_closure=0x3d9f0d8 <ZCMain_main_closure>, rts_config=...) at
 rts\RtsMain.c:72
 }}}

 But since it's a release build everything has been optimized out. I
 started a debug build of 8.6.3 to see.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/16057#comment:3>
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