[GHC] #15529: runtime bug when profiling retainers

[GHC]

#15529: runtime bug when profiling retainers
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        Reporter:  flip101           |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:  8.6.1
       Component:  Compiler          |              Version:  8.4.3
      Resolution:                    |             Keywords:
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):

 Ugh, we really ought to be printing ought what closure types are tripping
 up these RTS panics. I've submitted Phab:D5072 to do so for `pop()` at
 least.

 With a version of GHC built with Phab:D5072 applied, if I try running
 `vfix +RTS -hr -sstderr`, then I get the following information:

 {{{
 vfix: internal error: Invalid object *c in pop(): 62
     (GHC version 8.7.20180816 for x86_64_unknown_linux)
     Please report this as a GHC bug:
 http://www.haskell.org/ghc/reportabug
 Aborted (core dumped)
 }}}

 It looks like closure type 62
 [http://git.haskell.org/ghc.git/blob/5238f204482ac7f05f4e2d2e92576288cc00d42d:/includes/rts/storage/ClosureTypes.h#l84
 corresponds to] `SMALL_MUT_ARR_PTRS_FROZEN_CLEAN`. Any ideas there?

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15529#comment:1>
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