[GHC] #10762: On Windows, out-of-codepage characters can cause GHC build to fail

[GHC]

#10762: On Windows, out-of-codepage characters can cause GHC build to fail
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        Reporter:  snoyberg      |                   Owner:  snoyberg
            Type:  bug           |                  Status:  closed
        Priority:  normal        |               Milestone:
       Component:  Compiler      |                 Version:  7.10.2
      Resolution:  fixed         |                Keywords:
Operating System:  Windows       |            Architecture:  x86_64 (amd64)
 Type of failure:  None/Unknown  |               Test Case:
      Blocked By:                |                Blocking:
 Related Tickets:  #6037         |  Differential Revisions:
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Comment (by Ben Gamari <ben@…>):

 In [changeset:"1b56c40578374a15b4a2593895710c68b0e2a717/ghc"
 1b56c405/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="1b56c40578374a15b4a2593895710c68b0e2a717"
 Respect GHC_CHARENC environment variable #10762

 Only supports UTF-8 as a value right now. I expect some discussion to go
 on around the naming of this variable and whether it's valid to backport
 it to GHC 7.10 (which would be my preference). The motivation here is
 that, when capturing the output of GHC to a file, we often want to
 ensure that the output is UTF-8, regardless of the actual character
 encoding of the terminal/console.

 On the other hand, we don't want to necessary change the
 terminal/console encoding. The reason being:

 * On Windows, this requires a global-esque change to the console
   codepage, which adversely affects other processes in the same console

 * On all OSes, this can break features like smart quote auto-detection.

 Test Plan:
 Set LANG to C, GHC_CHARENC to UTF-8, and compile a Haskell source
 file with a non-ASCII warning produced. The output who include the UTF-8
 sequence instead of replacing it with ?.

 Reviewers: austin, rwbarton, bgamari

 Reviewed By: bgamari

 Subscribers: hsyl20, thomie

 Differential Revision: https://phabricator.haskell.org/D1167

 GHC Trac Issues: #10762
 }}}

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10762#comment:16>
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