id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc	os	architecture	failure	difficulty	testcase	blockedby	blocking	related
2449	panic with GeneralizedNewtypeDeriving and a .hs-boot file	igloo	igloo	"With `A.hs-boot`:
{{{
module A where

data A
    deriving Show
}}}
We can get a panic:
{{{
$ ghc -c -XGeneralizedNewtypeDeriving A.hs-boot

A.hs-boot:5:13:ghc: panic! (the 'impossible' happened)
  (GHC version 6.9.20080716 for x86_64-unknown-linux):
        newTyConEtadRhs main:A.A{tc r6K}

Please report this as a GHC bug:  http://www.haskell.org/ghc/reportabug
}}}
"	bug	closed	normal	6.10.1	Compiler	6.9	fixed			Unknown/Multiple	Unknown/Multiple		Unknown	drvfail016