Excerpts from Henk-Jan van Tuyl's message of Fri Jun 19 09:06:50 -0500 2009: > > L.S., > > I am trying to run a program in GHCi, but I get a meesage that an object > file is loaded twice; it appears that two different versions of package > "process" are loaded, see the session text below. How can I solve this? > > > GHCi, version 6.10.1: http://www.haskell.org/ghc/ :? for help > Loading package ghc-prim ... linking ... done. > Loading package integer ... linking ... done. > Loading package base ... linking ... done. > Prelude> :load "Main.lhs" > [1 of 1] Compiling Main ( Main.lhs, interpreted ) > Ok, modules loaded: Main. > *Main> :main > Loading package syb ... linking ... done. > Loading package base-3.0.3.0 ... linking ... done. > Loading package array-0.2.0.0 ... linking ... done. > Loading package containers-0.2.0.0 ... linking ... done. > Loading package bytestring-0.9.1.4 ... linking ... done. > Loading package old-locale-1.0.0.1 ... linking ... done. > Loading package old-time-1.0.0.1 ... linking ... done. > Loading package filepath-1.1.0.1 ... linking ... done. > Loading package Win32-2.2.0.0 ... linking ... done. > Loading package directory-1.0.0.2 ... linking ... done. > Loading package random-1.0.0.1 ... linking ... done. > Loading package time-1.1.2.2 ... linking ... done. > Loading package stm-2.1.1.2 ... linking ... done. > Loading package split-0.1.1 ... linking ... done. > Loading package HUnit-1.2.0.3 ... linking ... done. > Loading package QuickCheck-1.2.0.0 ... linking ... done. > Loading package process-1.0.1.1 ... linking ... done. > Loading package haskell98 ... linking ... done. > Loading package mtl-1.1.0.2 ... linking ... done. > Loading package parsec-2.1.0.1 ... linking ... done. > Loading package network-2.2.0.1 ... linking ... done. > Loading package hslogger-1.0.7 ... linking ... done. > Loading package process-1.0.1.0 ... > > GHCi runtime linker: fatal error: I found a duplicate definition for symbol > _runInteractiveProcess > whilst processing object file > C:\Programs\ghc\ghc-6.10.1\process-1.0.1.0\HSprocess-1.0.1.0.o > This could be caused by: > * Loading two different object files which export the same symbol > * Specifying the same object file twice on the GHCi command line > * An incorrect `package.conf' entry, causing some object to be > loaded twice. > GHCi cannot safely continue in this situation. Exiting now. Sorry. > >
The easiest solution would simply be to 'ghc-pkg unregister process-1.0.1.1', and then rebuild all the packages that depend on it against process-1.0.1.0. The reason this is happening is simply because you have two libraries you depend on, each of which depends on a different version of process. It's a fairly annoying error, that is prone to happen when you have upgraded versions of GHC's bootlibs (i.e. necessary libraries for GHC installation.) Austin _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe