[GHC] #8809: Prettier error messages?

[GHC]

#8809: Prettier error messages?
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        Reporter:  joelteon          |                Owner:
            Type:  feature request   |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  7.9
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
  #8809,#10073,#10179,#12906         |
       Wiki Page:                    |
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Comment (by Tamar Christina <tamar@…>):

 In [changeset:"847d229346431483b99adcff12e46c7bf6af15da/ghc"
 847d2293/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="847d229346431483b99adcff12e46c7bf6af15da"
 Color output is wreaking havoc on test results

 Summary:
 D2716 introduced colors into the output of GHC.
 These color ourputs are done using escape characters output
 to the terminal.

 These however are wreaking havoc on the testsuite output as now
 no stderr with a warning or error will match anymore.

 Instead of accepting the new codes as expected values instead I
 turn them off. So the testsuite is consistent on platforms/terminals we
 don't support colors on.

 Test Plan:
 any test that outputs colors. e.g.

 make test TEST=T9576

 Reviewers: austin, Rufflewind, bgamari

 Subscribers: thomie, #ghc_windows_task_force

 Differential Revision: https://phabricator.haskell.org/D2787

 GHC Trac Issues: #8809
 }}}

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8809#comment:41>
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