id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc	os	architecture	failure	difficulty	testcase	blockedby	blocking	related
7338	Duplicate type signature not reported	evincarofautumn	michalt	"Under 7.4.1, the following snippet compiles without error:

{{{
a, a :: Int
a = 0
}}}

It should issue the usual “duplicate type signature” diagnostic.

[http://hackage.haskell.org/trac/ghc/changeset/82cd019e0ccf9c097e54b80cc94401863ee98ecd 82cd019e] is probably relevant here.
"	bug	closed	normal		Compiler	7.4.1	fixed			Unknown/Multiple	x86	GHC accepts invalid program	Unknown	rename/should_fail/T7338, T7338a			#5589