[GHC] #14508: Bring up Appveyor for Windows CI

[GHC]

#14508: Bring up Appveyor for Windows CI
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           Reporter:  bgamari        |             Owner:  bgamari
               Type:  task           |            Status:  new
           Priority:  normal         |         Milestone:
          Component:  Continuous     |           Version:  8.2.1
  Integration                        |
           Keywords:                 |  Operating System:  Unknown/Multiple
       Architecture:                 |   Type of failure:  None/Unknown
  Unknown/Multiple                   |
          Test Case:                 |        Blocked By:
           Blocking:                 |   Related Tickets:
Differential Rev(s):                 |         Wiki Page:
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 The current plan is to move to Appveyor for CI on Windows.

 Mateusz has a first [[https://github.com/tweag/ghc/blob/tweag/circleci-
 macos/appveyor.yml|stab]] at a configuration. Unfortunately it looks like
 we will far-exceed the one-hour default build time limit. It appears they
 Appveyor [[https://github.com/appveyor/ci/issues/517
 |does give]] extensions to open-source projects, but typically only extend
 to 1.5 hours. It's unlikely that this will be sufficient as even my local
 Windows builds take ~1.75 hours.

 It appears that Rust has found a way around this as their
 [[https://ci.appveyor.com/project/rust-lang/rust/history|builds]]
 routinely last ~2 hours.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14508>
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