id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc	os	architecture	failure	difficulty	testcase	blockedby	blocking	related
3227	Can't specify type signature of value typed with type families	Ashley Yakeley		"Compiling this:
{{{
{-# LANGUAGE TypeFamilies #-}
module Bug where
  class C a where
    type T a
	
  p :: T a
  p = undefined

  q :: T a
  q = p
}}}
give this:
{{{
$ ghc -c Bug.hs -o Bug.o

Bug.hs:10:6:
    Couldn't match expected type `T a1' against inferred type `T a'
    In the expression: p
    In the definition of `q': q = p
}}}
It compiles successfully if the type signature for `q` is omitted.
{{{
$ ghc --version
The Glorious Glasgow Haskell Compilation System, version 6.10.3
$ uname -a
Linux glastonbury 2.6.28-12-generic #43-Ubuntu SMP Fri May 1 19:31:32 UTC 2009 x86_64 GNU/Linux
}}}
"	bug	closed	normal		Compiler	6.10.3	duplicate			Linux	x86_64 (amd64)		Unknown