[GHC] #10411: Neighbour let-bindings are not reported as relevant

[GHC]

#10411: Neighbour let-bindings are not reported as relevant
-------------------------------------+-------------------------------------
              Reporter:  Feuerbach   |             Owner:
                  Type:  bug         |            Status:  new
              Priority:  normal      |         Milestone:
             Component:  Compiler    |           Version:  7.10.1
              Keywords:              |  Operating System:  Unknown/Multiple
          Architecture:              |   Type of failure:  None/Unknown
  Unknown/Multiple                   |        Blocked By:
             Test Case:              |   Related Tickets:
              Blocking:              |
Differential Revisions:              |
-------------------------------------+-------------------------------------
 {{{
 > :set -fno-max-relevant-binds
 > let a = True; b = _ in undefined

 <interactive>:3:19:
     Found hole ‘_’ with type: t1
     Where: ‘t1’ is a rigid type variable bound by
                 the inferred type of b :: t1 at <interactive>:3:15
     Relevant bindings include
       b :: t1 (bound at <interactive>:3:15)
       it :: t (bound at <interactive>:3:1)
     In the expression: _
     In an equation for ‘b’: b = _
     In the expression:
       let
         a = True
         b = _
       in undefined

 }}}

 Somehow a is not there, even though b itself is.

 Tested with 7.8.3 and 7.10.1

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10411>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler