[GHC] #11604: Build system fails after submodule update

[GHC]

#11604: Build system fails after submodule update
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        Reporter:  niteria           |                Owner:
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Build System      |              Version:  8.1
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by thomie):

 I did not manage to reproduce this issue, using the steps from comment:6.

 The only difference is that I'm using 7.10.3 instead of 7.10.2. Could that
 be it?

 I did see this, but disabled it by adding `libraries/transformers_dist-
 install_EXTRA_HC_OPTS += -Wno-orphan` to `mk/warnings.mk`, as suggested in
 #11600.
 {{{
 "inplace/bin/ghc-stage1" -hisuf hi -osuf  o -hcsuf hc -static  -O0 -H64m
 -Wall  -Werror    -this-unit-id transformers-0.5.2.0 -hide-all-packages -i
 -ilibraries/transformers/. -ilibraries/transformers/dist-install/build
 -ilibraries/transformers/dist-install/build/autogen
 -Ilibraries/transformers/dist-install/build -Ilibraries/transformers/dist-
 install/build/autogen -Ilibraries/transformers/.    -optP-include
 -optPlibraries/transformers/dist-install/build/autogen/cabal_macros.h
 -package-id base-4.9.0.0 -XHaskell98 -O0  -no-user-package-db -rtsopts
 -Wno-unused-matches -Wno-unused-imports -Wno-redundant-constraints -Wno-
 deprecated-flags     -Wnoncanonical-monad-instances  -odir
 libraries/transformers/dist-install/build -hidir libraries/transformers
 /dist-install/build -stubdir libraries/transformers/dist-install/build
 -dynamic-too -c libraries/transformers/./Control/Monad/Trans/Error.hs -o
 libraries/transformers/dist-install/build/Control/Monad/Trans/Error.o
 -dyno libraries/transformers/dist-
 install/build/Control/Monad/Trans/Error.dyn_o

 libraries/transformers/Control/Monad/Trans/Error.hs:95:1: warning:
     Orphan instance: instance [safe] Error e => Alternative (Either e)
     To avoid this
         move the instance declaration to the module of the class or of the
 type, or
         wrap the type with a newtype and declare the instance on the new
 type.

 libraries/transformers/Control/Monad/Trans/Error.hs:100:1: warning:
     Orphan instance: instance [safe] Error e => MonadPlus (Either e)
     To avoid this
         move the instance declaration to the module of the class or of the
 type, or
         wrap the type with a newtype and declare the instance on the new
 type.
 }}}

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11604#comment:7>
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