Christian Gosch | 21 Feb 22:32 2013

GHC panicking when using -fext-core -O2

Hi Cafe,

when I try to create core files with the above options, ghc panics with 
this message:

ghc: panic! (the 'impossible' happened)
   (GHC version 7.6.2 for x86_64-unknown-linux):
     make_exp (App _ (Coercion _))

Please report this as a GHC bug:

I tried this with 7.4.1 and with 7.6.2.
Does anyone have an idea why this could happen, without looking at the 
code I am trying to compile?

Thanks for any hint,