[GHC] #10021: Add "Error:" prefix for compile-time error messages

[GHC]

#10021: Add "Error:" prefix for compile-time error messages
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        Reporter:  k-bx              |                   Owner:  k-bx
            Type:  feature request   |                  Status:  new
        Priority:  normal            |               Milestone:  7.12.1
       Component:  Compiler          |                 Version:  7.8.4
      Resolution:                    |                Keywords:
Operating System:  Unknown/Multiple  |            Architecture:
 Type of failure:  None/Unknown      |  Unknown/Multiple
      Blocked By:                    |               Test Case:
 Related Tickets:                    |                Blocking:
                                     |  Differential Revisions:
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Comment (by k-bx):

 Just wanted to update a little on my work. I had one week off and will
 have one more now, so things are slower than I wanted, otherwise here are
 how things going:

 I wrote two scripts to help me working on this issue. First is turtle-
 replace-stdout.hs, second is turtle-review.hs. Here they are:
 https://gist.github.com/k-bx/fe7027c919980eb9b7f0

 When you run first one, it will replace (almost) all failed test's actual
 output with expected one. Afterwards, you should run second script, which
 will review trivial cases and git-add them. Finally, the ones that are
 left were reviewed manually.

 Currently status is that few tests still fail upon validate, and few will
 probably become failing after rebase. Anyway, will finish the work quickly
 after I come back from Norway.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10021#comment:14>
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