internal error: ARR_WORDS object entered!
In ghci,
:m Data.Complex.Cyclotomic
goldenRatio
produces the error.
<interactive>: internal error: ARR_WORDS object entered!
(GHC version 7.8.3 for x86_64_unknown_linux)
Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug
Aborted (core dumped)