[GHC] #11370: Redundant superclass warnings being included in -Wall destroys the "3 Release Policy"

[GHC]

#11370: Redundant superclass warnings being included in -Wall destroys the "3
Release Policy"
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        Reporter:  ekmett            |                Owner:
            Type:  bug               |               Status:  new
        Priority:  highest           |            Milestone:  8.0.1
       Component:  Compiler (Type    |              Version:  7.10.3
  checker)                           |
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:  #11369, #11429    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by simonpj):

 > 2) Remove it from both the default constraint set and -Wall.

 Doesn't that mean that 8.2 will be in ''precisely'' the same situation as
 8.0, and we'll just have the identical conversation then?

 What is `-Wlint`?  Is it the same as `-Weverything`?  What does it mean?
 Perhaps this:
  * Default warnings are what you get by default.  Is there a flag
 `-Wdefault`?
  * `-Wall` means a larger set.
  * `-Weverything` means the entire set.

 Plus there is some protocol that a new warning always starts in
 `-Weverything`; may move in the next release to `-Wall`; and may move in
 the release after that to the default set.  Both moves are a judgement
 call.

 Maybe I have this wrong. It would be super-helpful if someone could lay
 our the entire proposal.  It doesn't look hard to implement in 8.0 if I
 have it roughly right, and someone is willing to step up to do it.

 Simon

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11370#comment:10>
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