[GHC] #7456: GHC API displays linker messages to stdout instead of via log_action

[GHC]

#7456: GHC API displays linker messages to stdout instead of via log_action
----------------------------+-----------------------------------------------
Reporter:  MikolajKonarski  |          Owner:  duncan, MikolajKonarski
    Type:  bug              |         Status:  new                    
Priority:  normal           |      Component:  GHC API                
 Version:  7.4.2            |       Keywords:                         
      Os:  Linux            |   Architecture:  x86_64 (amd64)         
 Failure:  Other            |      Blockedby:                         
Blocking:                   |        Related:                         
----------------------------+-----------------------------------------------
 At least in the LinkInMemory mode, GHC API displays linker messages, such
 as

 {{{
 Loading package ghc-prim ... linking ... done.
 Loading package integer-gmp ... linking ... done.
 }}}

 on stdout instead of using the log_action handler for them, just as for
 all the other kinds of messages. Moreover, I haven't found any way of
 suppressing these messages apart of setting verbosity=0, which turns off
 other important messages. I can see no GHC flags that does this and this
 linker does not accept any special linker flags. I don't know the policy
 about severity levels, but I suppose severity SevOutput could be fine for
 these messages, by similarity to "compiling M ... done." messages which
 have such severity.

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7456>
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