[GHC] #4806: Make error message more user friendly when module is not found because package is unusable

[GHC]

#4806: Make error message more user friendly when module is not found because
package is unusable
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        Reporter:  mitar             |                Owner:  (none)
            Type:  feature request   |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  7.0.1
      Resolution:                    |             Keywords:  newcomer
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D4783
       Wiki Page:                    |
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Comment (by sgillespie):

 Replying to [comment:27 Phyx-]:
 > I would change the first part to be more precise
 >
 > `Could not find module ‘Control.Monad.Random’` into something like
 `Could not load module ‘Control.Monad.Random’` since the message is a bit
 contradictory saying it couldn't find it yet it's part of a package it
 knows about.

 I toyed with this a bit, using "Could not load module" for hidden and
 unusable packages. It broke hundreds of tests, and I'm a bit uncomfortable
 with that. For that reason, I think it's best not to mess with that for
 now.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/4806#comment:31>
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