id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc	os	architecture	failure	difficulty	testcase	blockedby	blocking	related
4302	Impossible when deriving empty data declaration	mitar		"When trying to load following code into GHCi I get an error:

{{{
ghc: panic! (the 'impossible' happened)
  (GHC version 6.12.3 for x86_64-unknown-linux):
	TcGenDeriv:mk_FunBind
}}}

Code is:

{{{
{-# LANGUAGE StandaloneDeriving, EmptyDataDecls #-}
module Test where
data Test
deriving instance Show (Test)
}}}

Probably `Test` cannot be made instance of `Show` but still error should be less fatal. ;-)"	bug	closed	normal	7.4.1	Compiler	6.12.3	fixed		mmitar@…	Linux	x86_64 (amd64)	None/Unknown		deriving/should_compile/T4302