[GHC] #15968: configure doesn't error out when --enable-dwarf-unwind is given but libdw cannot be found

[GHC]

#15968: configure doesn't error out when --enable-dwarf-unwind is given but libdw
cannot be found
-------------------------------------+-------------------------------------
        Reporter:  nh2               |                Owner:  (none)
            Type:  bug               |               Status:  patch
        Priority:  normal            |            Milestone:  8.8.1
       Component:  Build System      |              Version:  8.6.2
  (make)                             |
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  Other             |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D5424
       Wiki Page:                    |
-------------------------------------+-------------------------------------
Changes (by harpocrates):

 * status:  new => patch
 * differential:   => Phab:D5424


-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15968#comment:1>
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