[GHC] #4144: Exception: ToDo: hGetBuf - when using custom handle infrastructure

[GHC]

#4144: Exception: ToDo: hGetBuf - when using custom handle infrastructure
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        Reporter:  AntoineLatter     |                Owner:
            Type:  bug               |               Status:  new
        Priority:  high              |            Milestone:  8.2.1
       Component:  Core Libraries    |              Version:  7.6.1
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  Runtime crash     |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Changes (by bgamari):

 * cc: ekmett (added)
 * milestone:  8.0.1 => 8.2.1


Old description:

> When trying to use the custom handle infrastructure, hGetContents fails
> like so:
>
> *** Exception: ToDo: hGetBuf
>
> This exception occurs twice in GHC.IO.Handle.Text
>
> The handle implementation I'm using is attached.
>
> It would be neat if I could pass along some witness that my device
> implements RawDevice, then we could just run the same code that we use
> for file-descriptors. But I'd be happy enough with a general solution, as
> I just plan to use this for testing.

New description:

 When trying to use the custom handle infrastructure, `hGetContents` fails
 like so:
 {{{
 *** Exception: ToDo: hGetBuf
 }}}
 This exception occurs twice in `GHC.IO.Handle.Text`

 The handle implementation I'm using is attached.

 It would be neat if I could pass along some witness that my device
 implements `RawDevice`, then we could just run the same code that we use
 for file-descriptors. But I'd be happy enough with a general solution, as
 I just plan to use this for testing.

--

Comment:

 This won't be happening for 8.0.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/4144#comment:23>
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