Excerpts from Marcelo Sousa's message of Sun Sep 27 14:13:43 +0200 2009:

Hey guys,

I'm trying to install yi using cabal but I got this error. Any ideas how to solve it?! I'm using ghc-6.10.1 and cabal-install version 0.6.2 using version 1.6.0.2 of the Cabal library.

This means that you either have to downgrade data-accessor, or trash out the Category instance in Yi/Prelude.hs line 182.

$ cabal install yi Resolving dependencies... Configuring yi-0.6.1... Preprocessing library yi-0.6.1... Preprocessing executables for yi-0.6.1... Building yi-0.6.1... [ 1 of 120] Compiling System.FriendlyPath ( System/FriendlyPath.hs, dist/build/System/FriendlyPath.o ) [ 2 of 120] Compiling Shim.ProjectContent ( Shim/ProjectContent.hs, dist/build/Shim/ProjectContent.o ) [ 3 of 120] Compiling Parser.Incremental ( Parser/Incremental.hs, dist/build/Parser/Incremental.o ) [ 4 of 120] Compiling Data.Trie ( Data/Trie.hs, dist/build/Data/Trie.o ) [ 5 of 120] Compiling Data.DelayList ( Data/DelayList.hs, dist/build/Data/DelayList.o ) [ 6 of 120] Compiling Data.Rope ( Data/Rope.hs, dist/build/Data/Rope.o ) [ 7 of 120] Compiling Data.Prototype ( Data/Prototype.hs, dist/build/Data/Prototype.o ) [ 8 of 120] Compiling HConf.Utils ( HConf/Utils.hs, dist/build/HConf/Utils.o ) [ 9 of 120] Compiling HConf.Paths ( HConf/Paths.hs, dist/build/HConf/Paths.o ) [ 10 of 120] Compiling Paths_yi ( dist/build/autogen/Paths_yi.hs, dist/build/Paths_yi.o ) [ 11 of 120] Compiling HConf ( HConf.hs, dist/build/HConf.o ) [ 12 of 120] Compiling Yi.Char.Unicode ( Yi/Char/Unicode.hs, dist/build/Yi/Char/Unicode.o ) [ 13 of 120] Compiling Yi.UI.Common[boot] ( Yi/UI/Common.hs-boot, dist/build/Yi/UI/Common.o-boot ) [ 14 of 120] Compiling Yi.String ( Yi/String.hs, dist/build/Yi/String.o ) [ 15 of 120] Compiling Yi.Monad ( Yi/Monad.hs, dist/build/Yi/Monad.o ) [ 16 of 120] Compiling Yi.Keymap.Completion ( Yi/Keymap/Completion.hs, dist/build/Yi/Keymap/Completion.o ) [ 17 of 120] Compiling Yi.Editor[boot] ( Yi/Editor.hs-boot, dist/build/Yi/Editor.o-boot ) [ 18 of 120] Compiling Yi.Debug ( Yi/Debug.hs, dist/build/Yi/Debug.o ) [ 19 of 120] Compiling Yi.Prelude ( Yi/Prelude.hs, dist/build/Yi/Prelude.o )

Yi/Prelude.hs:182:9: Duplicate instance declarations: instance Category Accessor.T -- Defined at Yi/Prelude.hs:182:9-38 instance Category Accessor.T -- Defined in data-accessor-0.2.1:Data.Accessor.Private cabal: Error: some packages failed to install: yi-0.6.1 failed during the building phase. The exception was: exit: ExitFailure 1

-- Nicolas Pouillard http://nicolaspouillard.fr