GC assertion failure in reactive program

In the same vein as bug #3279, this time I've triggered an assertion failure in the GC by adding Debug.Trace.trace expressions.

The exact same failure occurs in both 6.10.3 and 6.11, apparently completely deterministically.

A darcs patch to add the crash to reactive, and a program to trigger it, are both attached.

Expected output:

svein@eris ~ $ ./crash
<Imp NoBound 2.0,1.0>
<Imp NoBound 2.5,2.0>
<Imp NoBound 3.2,3.0>
<Imp NoBound 3.7,4.0>
"never-never"
crash: internal error: scavenge_one: strange object 28
    (GHC version 6.11.20090605 for x86_64_unknown_linux)
    Please report this as a GHC bug:  http://www.haskell.org/ghc/reportabug
Aborted

Trac metadata

Trac field	Value
Version	6.11
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Runtime System
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