[GHC] #14519: Exponential runtime performance regression in GHC 8.2 + Data.Text.Lazy + Text.RE.TDFA

[GHC]

#14519: Exponential runtime performance regression in GHC 8.2 + Data.Text.Lazy +
Text.RE.TDFA
-------------------------------------+-------------------------------------
        Reporter:  ntc2              |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.2.2
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  Runtime           |            Test Case:
  performance bug                    |  https://github.com/ntc2/ghc-8.2.1
                                     |  -regex-lazy-text-bug
      Blocked By:                    |             Blocking:
 Related Tickets:  13745             |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by ntc2):

 Having "unusable due to shadowed dependencies" trouble with the GHC 8.2.1
 I built from source when trying to build my test code. Links to possibly
 related issues and a patch:

 - https://github.com/haskell/cabal/issues/4728
 - https://github.com/commercialhaskell/stack/issues/3554
 - https://phabricator.haskell.org/D4159
 - https://ghc.haskell.org/trac/ghc/ticket/14381

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14519#comment:2>
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