id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc	os	architecture	failure	difficulty	testcase	blockedby	blocking	related
959	"Debugging info(?) leaks out: ""Urk! Inventing strangely-kinded void TyCon"""	igloo		"With GHC 6.6, this module:
{{{
module G where

testL = foo undefined

class Foo t where
    foo :: m a -> t m a
}}}
leaks some debugging info(?):
{{{
Urk! Inventing strangely-kinded void TyCon:
    :t{tc ae2}
    (* -> *) -> * -> *

tmp.hs:4:8:
    Ambiguous type variable `t' in the constraint:
      `Foo t' arising from use of `foo' at tmp.hs:4:8-20
    Possible cause: the monomorphism restriction applied to the following:
      testL :: forall (m :: * -> *) a. t m a (bound at tmp.hs:4:0)
    Probable fix: give these definition(s) an explicit type signature
                  or use -fno-monomorphism-restriction
}}}

I haven't managed to get this message in an acceptable program.

(found by fasta on IRC)"	bug	closed	normal	_|_	Compiler (Type checker)	6.6	fixed		Ben.Lippmeier@…	Unknown/Multiple	Unknown/Multiple		Unknown	tcfail188