--show-iface hangs on certain .hi files

In a GHC build, try

inplace/bin/ghc-stage2 --show-iface array/dist-install/build/Data/Array/Base.hi

This hangs for me, right after

b0318967c2f8fdf2005760546e36e780
  $fIArrayUArrayBool_$cunsafeAccum :: forall i e'.
                                      GHC.Arr.Ix i =>
                                      (GHC.Bool.Bool -> e' -> GHC.Bool.Bool)
                                      -> Data.Array.Base.UArray i GHC.Bool.Bool
                                      -> [(GHC.Types.Int, e')]
                                      -> Data.Array.Base.UArray i GHC.Bool.Bool
    {- Arity: 4, HasNoCafRefs, Strictness: ALU(LLLL)L,
       Inline: INLINE{3},^C

and the GHC process is uninteruptible, which suggests it has gone into an infinite non-allocating loop.

Appears to be HEAD only.

Trac metadata

Trac field	Value
Version	6.13
Type	Bug
TypeOfFailure	OtherFailure
Priority	high
Resolution	Unresolved
Component	Compiler
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