[GHC] #12406: New not-in-scope behaviour + deferred typed holes = disappearing error messages

[GHC]

#12406: New not-in-scope behaviour + deferred typed holes = disappearing error
messages
-------------------------------------+-------------------------------------
        Reporter:  ertes             |                Owner:  ak3n
            Type:  bug               |               Status:  merge
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.0.1
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  Incorrect         |            Test Case:
  warning at compile-time            |  typecheck/should_fail/T12406
      Blocked By:                    |             Blocking:
 Related Tickets:  #12170            |  Differential Rev(s):  Phab:D2451
       Wiki Page:                    |
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Comment (by Ben Gamari <ben@…>):

 In [changeset:"6071ecf4ff7501c70456c1448fa2f78e91bc8078/ghc"
 6071ecf4/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="6071ecf4ff7501c70456c1448fa2f78e91bc8078"
 Not-in-scope variables are always errors

 This fixes Trac #12406.  A not-in-scope error shoudl be an error
 even if you have -fdefer-typed-holes.

 (cherry picked from commit efc0372a157eadeee58bbada77c64d53590e04af)
 }}}

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12406#comment:8>
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