[GHC] #11505: Boot file problem

28 Jan 2016


      #11505: Boot file problem
-------------------------------------+-------------------------------------
           Reporter:  augustss       |             Owner:
               Type:  bug            |            Status:  new
           Priority:  normal         |         Milestone:
          Component:  Compiler       |           Version:  7.8.3
           Keywords:                 |  Operating System:  Unknown/Multiple
       Architecture:                 |   Type of failure:  None/Unknown
  Unknown/Multiple                   |
          Test Case:                 |        Blocked By:
           Blocking:                 |   Related Tickets:
Differential Rev(s):                 |         Wiki Page:
-------------------------------------+-------------------------------------
 Here are two modules and a boot file.
 Compile by
 {{{
 ghc -c Foo.hs-boot; ghc -c Bar.hs; ghc -c Foo.hs
 }}}
 and observe this error message
 {{{
 Foo.hs:12:1:
     Type constructor `Foo' has conflicting definitions in the module
     and its hs-boot file
     Main module: data Foo = Foo {x :: {-# UNPACK #-} !Int}
     Boot file:   data Foo = Foo {x :: !Int}
 }}}
 But the definitions are not conflicting, they are identical.

 Foo.hs-boot:
 {{{
 module Foo where
 data Foo = Foo { x :: {-# UNPACK #-} !Int }
 }}}

 Foo.hs:
 {{{
 module Foo where
 import Bar
 data Foo = Foo { x :: {-# UNPACK #-} !Int }
 }}}

 Bar.hs:
 {{{
 module Bar where
 import {-# SOURCE #-} Foo
 }}}

 Removing the unbox pragma gives the even more perplexing:
 {{{
 Foo.hs:3:1:
     Type constructor `Foo' has conflicting definitions in the module
     and its hs-boot file
     Main module: data Foo = Foo {x :: !Int}
     Boot file:   data Foo = Foo {x :: !Int}
 }}}

--
Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11505
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