The duplicate definition error appears when I compile Main.hs and execute it. But when I run it with runghc the behaviour is different. It works well:
runghc Main.hs 3
Any idea? is this a bug of hs-plugins? it is just something expected??
2008/12/6 Alberto G. Corona
I have a web server which load server extensions. these extensions eval-uate configuration files that contains code (user-editable workflow descriptions). The problem is that I need common definitions (inside imported modules) for the extensions and for the configuration files. This is not permitted by ha-plugins.
The minimal code example are the files below. main loads eval.hs , that evaluate a expression. The common definitions are in Include.hs. The error is:
*GHCi runtime linker: fatal error: I found a duplicate definition for symbol Include_sum1_srt whilst processing object file /home/magocoal/haskell/devel/votesWorkflow/src/unused/tests/Include.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. *
** Do you kno how to solve the problem while maintaining the functionality?
-------Include.hs------- module Include where
sum [x,y]= x+y
------Main.hs----- module Main where
import Include import System.Plugins
main= do s <-loadExec "eval.o" "mainc" print s
loadExec:: String-> String->IO String loadExec file method = do
mv <- load file ["."] [] method case mv of LoadSuccess mod v -> v :: IO String LoadFailure msg -> return $ concat msg
------------Eval.hs--------
module Eval(mainc) where import System.IO.Unsafe import System.Eval.Haskell
mainc= do i <- unsafeEval_ "sum1 [1,2]" ["Include"] [] []["."] :: IO (Either [String] Int) return $ show i