[GHC] #15068: Small number of test case failures on Ubuntu Bionic (GCC 7.3)

[GHC]

#15068: Small number of test case failures on Ubuntu Bionic (GCC 7.3)
-------------------------------------+-------------------------------------
        Reporter:  jrp               |                Owner:  (none)
            Type:  bug               |               Status:  merge
        Priority:  highest           |            Milestone:  8.6.1
       Component:  Compiler          |              Version:  8.4.1
  (CodeGen)                          |
      Resolution:  fixed             |             Keywords:
Operating System:  Linux             |         Architecture:  x86_64
                                     |  (amd64)
 Type of failure:  Incorrect result  |            Test Case:  T13658
  at runtime                         |  T14779a T14779b T14868 debug
                                     |  parsing001
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D4654
       Wiki Page:                    |
-------------------------------------+-------------------------------------

Comment (by hvr):

 Replying to [comment:35 YitzGale]:
 > Thanks! Is the fix something that can be backported to previous versions
 of GHC?

 It can be done, and this is typically something that falls into the scope
 of packagers and distributors if they need to target affected toolchains;
 in fact this is what I did in

  - GHC 8.2.2 (c.f.
 https://launchpad.net/~hvr/+archive/ubuntu/ghc/+sourcepub/9083599
 /+listing-archive-extra)
  - GHC 8.4.2 (c.f.
 https://launchpad.net/~hvr/+archive/ubuntu/ghc/+sourcepub/9083600
 /+listing-archive-extra)

 This has also happened in the past; without such backporting of compat-
 fixes I wouldn't be able to provide GHC versions ranging back to GHC 7.0.1
 for the latest Debian & Ubuntu releases which had already made this
 necessary in the past thanks to evolving toolchains which broke
 assumptions made by GHC or happened to expose actual bugs, or were
 actually bugs in the C toolchain.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15068#comment:36>
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