"internal error: heapCencus, unknown object: 0" with retainer profiling

Compile the attached file as:

ghc --make retainer.hs -prof -rtsopts

And run it with:

./retainer +RTS -hr -V0

you get:

retainer: internal error: heapCensus, unknown object: 0
    (GHC version 7.0.4 for x86_64_unknown_linux)
    Please report this as a GHC bug:  http://www.haskell.org/ghc/reportabug

I found this test case while chasing a "Invalid object in isRetainer(): 39" problem, so this might be related to the ticket #4820 (closed). Also, although this particular case requires -V0 to reproduce, the original problem happened without -V0 as well.

Edited Mar 09, 2019 by Ian Lynagh -

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"internal error: heapCencus, unknown object: 0" with retainer profiling