id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc	os	architecture	failure	difficulty	testcase	blockedby	blocking	related
7164	"Confusing ""not a (visible) method"" warning when method name clashes with another definition"	joeyadams		"Given this code:

{{{
class Foo m where
    herp :: (a -> a) -> m b -> m b
    derp :: m a

derp :: Int
derp = 123
}}}

GHC 7.4.1, 7.4.2, and 7.6.0.20120810 (rc1) produce the following output:

{{{
not-visible-method.hs:3:5:
    `derp' is not a (visible) method of class `Foo'

not-visible-method.hs:6:1:
    Multiple declarations of `derp'
    Declared at: not-visible-method.hs:3:5
                 not-visible-method.hs:6:1
}}}

The second error makes sense, but the first one is bogus.  I'm defining class `Foo`!  If I remove the clashing `derp`, the module compiles.

GHC 7.0.3 and 7.2.2 produce the correct output."	bug	closed	normal		Compiler	7.6.1-rc1	fixed			Unknown/Multiple	Unknown/Multiple	Incorrect warning at compile-time	Unknown	rename/should_fail/T7164