[GHC] #2904: Broken pipe when quitting "ghc --show-iface file.hi | less"

[GHC]

#2904: Broken pipe when quitting "ghc --show-iface file.hi | less"
-----------------------------+----------------------------------------------
Reporter:  Syzygies          |          Owner:                  
    Type:  bug               |         Status:  new             
Priority:  normal            |      Component:  Compiler        
 Version:  6.10.1            |       Severity:  trivial         
Keywords:                    |       Testcase:                  
      Os:  Unknown/Multiple  |   Architecture:  Unknown/Multiple
-----------------------------+----------------------------------------------
 Here is an example of a very minor rough edge in ghc:
 {{{
 % ghc --show-iface Matrix.hi | less
 ghc: <stdout>: hFlush: resource vanished (Broken pipe)
 }}}
 If one quits ''less'' before reading all the output (a likely scenario),
 one sees this predictable error message.

 I'd argue that one should suppress this message, so users learn to pay
 attention to the messages they do see.

 A work-around is
 {{{
 % ghc --show-iface Matrix.hi 2> /dev/null | less
 }}}
 but this suppresses other messages one might want to see. My attempts at a
 more precise work-around get me into "damned if you do, damned if you
 don't" territory. For example,
 {{{
 % (ghc --show-iface Matrix.hi 2| grep -v 'Broken') | less
 }}}
 doesn't work.

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/2904>
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