[GHC] #7150: unjustified overlapping instances error

[GHC]

#7150: unjustified overlapping instances error
-------------------------+--------------------------------------------------
    Reporter:  maeder    |       Owner:                           
        Type:  bug       |      Status:  new                      
    Priority:  normal    |   Milestone:                           
   Component:  Compiler  |     Version:  7.6.1-rc1                
    Keywords:            |          Os:  Solaris                  
Architecture:  x86       |     Failure:  GHC rejects valid program
  Difficulty:  Unknown   |    Testcase:                           
   Blockedby:            |    Blocking:                           
     Related:            |  
-------------------------+--------------------------------------------------

Comment(by maeder):

 It's hard to reproduce, since some sources must be generated first.

 {{{
 svn co https://svn-agbkb.informatik.uni-bremen.de/Hets/trunk Hets
 cd Hets
 make
 }}}

 The minimal packages required are listed in http://trac.informatik.uni-
 bremen.de:8080/hets/browser/trunk/Hets.cabal but "cabal install" will not
 generate missing source files (and will try to install more packages if
 not tuned with -f options)!

 Therefore you need to call "make" and ignore "ghc-pkg: cannot find
 package" messages.

 (text and network packages needed patches) My current minimal packages are
 as follows:

 {{{
 -bash-3.00$ ghc-pkg list
 /local/home/maeder/lib/ghc-7.6.0.20120810/package.conf.d:
     Cabal-1.16.0
     array-0.4.0.1
     base-4.6.0.0
     bin-package-db-0.0.0.0
     binary-0.5.1.1
     bytestring-0.10.0.0
     containers-0.5.0.0
     deepseq-1.3.0.1
     directory-1.1.1.0
     filepath-1.3.0.1
     (ghc-7.6.0.20120810)
     ghc-prim-0.3.0.0
     (haskell2010-1.1.1.0)
     (haskell98-2.0.0.2)
     hoopl-3.9.0.0
     hpc-0.6.0.0
     integer-gmp-0.5.0.0
     mtl-2.1.2
     old-locale-1.0.0.5
     old-time-1.1.0.1
     pretty-1.1.1.0
     process-1.1.0.2
     rts-1.0
     template-haskell-2.8.0.0
     time-1.4.0.1
     transformers-0.3.0.0
     unix-2.6.0.0

 /home/maeder/.ghc/i386-solaris2-7.6.0.20120810/package.conf.d:
     aterm-0.1.0.1
     fgl-5.4.2.4
     network-2.3.0.14
     parsec-3.1.3
     text-0.11.2.2
     utf8-string-0.3.7
     xml-1.3.12

 -bash-3.00$ gmake
 ghc-pkg: cannot find package HaXml
 ghc-pkg: cannot find package HaXml
 ghc-pkg: cannot find package tar
 ghc-pkg: cannot find package glade
 ghc-pkg: cannot find package haskeline
 ghc-pkg: cannot find package hexpat
 ghc-pkg: cannot find package HTTP
 ghc-pkg: cannot find package uni-uDrawGraph
 ghc-pkg: cannot find package programatica
 ghc-pkg: cannot find package warp
 ghc-pkg: cannot find package wai-extra
 ghc-pkg: cannot find package parsec1
 ghc -optl-s -XTemplateHaskell -threaded -rtsopts --make -o hets hets.hs
 -fcontext-stack=26    -DNOHTTP -DUNIX        -DRDFLOGIC -DCASLEXTENSIONS
 -Wall -fwarn-tabs -fwarn-unrecognised-pragmas -fno-warn-orphans -fno-warn-
 unused-do-bind
 [474 of 627] Compiling Comorphisms.HasCASL2IsabelleHOL (
 Comorphisms/HasCASL2IsabelleHOL.hs, Comorphisms/HasCASL2IsabelleHOL.o )

 Comorphisms/HasCASL2IsabelleHOL.hs:61:44:
 ...
 }}}

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7150#comment:2>
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