[GHC] #14717: Hidden package hints no longer display

[GHC]

#14717: Hidden package hints no longer display
-------------------------------------+-------------------------------------
           Reporter:  snoyberg       |             Owner:  (none)
               Type:  bug            |            Status:  new
           Priority:  normal         |         Milestone:
          Component:  Compiler       |           Version:  8.2.2
           Keywords:                 |  Operating System:  Unknown/Multiple
       Architecture:                 |   Type of failure:  Poor/confusing
  Unknown/Multiple                   |  error message
          Test Case:                 |        Blocked By:
           Blocking:                 |   Related Tickets:
Differential Rev(s):                 |         Wiki Page:
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 This started as a mailing list thread: https://mail.haskell.org/pipermail
 /haskell-cafe/2018-January/128485.html. Dan Burton demonstrated a
 reproduction without any build tool.

 With GHC 8.0.2, when you try to use a module from a hidden package, you
 get an error message with a helpful hint to add the package to the build-
 depends. With GHC 8.2.2 (and I believe 8.2.1), it appears that this hint
 is no longer displayed. To demonstrate, I'll copy Dan's repro:

 {{{
 $ cat Main.hs
 module Main where
 import Data.Map
 main = putStrLn "It compiles"

 $ ghc-pkg list containers
 /usr/local/Cellar/ghc/8.2.2/lib/ghc-8.2.2/package.conf.d
     containers-0.5.10.2

 $ ghc --make -hide-all-packages -package base Main.hs
 [1 of 1] Compiling Main             ( Main.hs, Main.o )

 Main.hs:2:1: error:
     Could not find module ‘Data.Map’
     Use -v to see a list of the files searched for.
   |
 2 | import Data.Map
   | ^^^^^^^^^^^^^^^

 $ ghc --make -hide-all-packages -package base -package containers Main.hs
 [1 of 1] Compiling Main             ( Main.hs, Main.o )
 Linking Main ...
 }}}

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14717>
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