[GHC] #11109: build broken in libffi/ when `install-sh` is used

[GHC]

#11109: build broken in libffi/ when `install-sh` is used
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        Reporter:  hvr               |                Owner:
            Type:  bug               |               Status:  patch
        Priority:  normal            |            Milestone:  8.0.1
       Component:  Build System      |              Version:  7.10.2
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D1494
       Wiki Page:                    |
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Comment (by Ben Gamari <ben@…>):

 In [changeset:"3e2a4eefbed7002437c3f3ee340832a42f0b37f8/ghc" 3e2a4ee/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="3e2a4eefbed7002437c3f3ee340832a42f0b37f8"
 Fix broken build-system when libffi uses install-sh

 Reviewers: austin, bgamari

 Reviewed By: bgamari

 Subscribers: thomie

 Differential Revision: https://phabricator.haskell.org/D1494

 GHC Trac Issues: #11109
 }}}

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11109#comment:2>
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