[GHC] #14052: Significant GHCi speed regression with :module and `let` in GHC 8.2.1

[GHC]

#14052: Significant GHCi speed regression with :module and `let` in GHC 8.2.1
-------------------------------------+-------------------------------------
        Reporter:  RyanGlScott       |                Owner:  osa1
            Type:  bug               |               Status:  closed
        Priority:  high              |            Milestone:  8.4.2
       Component:  GHCi              |              Version:  8.2.1-rc2
      Resolution:  fixed             |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Runtime           |  Unknown/Multiple
  performance bug                    |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:  #11547            |  Differential Rev(s):  Phab:D4478
       Wiki Page:                    |
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Comment (by osa1):

 The conclusion was to not keep shadowed variables at all (because there's
 no reason for it), whether it's fast or slow. So really the fix for #11547
 is just a better error message (as mentioned in comment:22).

 sighingnow, would you be willing to open a new ticket for that and give it
 a try?

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14052#comment:25>
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