Hi I have code using the ghc-api that could be run in interactive mode prior to version 7 but now makes ghci crash with a linker error. Everything works fine if compiled before running. I don't know if this is a known issue or if I'm just using the api in the wrong way, but I thought that I might ask. To illustrate the problem, consider this simple example: t.hs:

import qualified GHC import qualified GHC.Paths

main = GHC.runGhcT (Just GHC.Paths.libdir) $ do -- begin initialize df0 <- GHC.getSessionDynFlags let df1 = df0{GHC.ghcMode = GHC.CompManager, GHC.hscTarget = GHC.HscInterpreted, GHC.ghcLink = GHC.LinkInMemory, GHC.verbosity = 0} _ <- GHC.setSessionDynFlags df1 -- begin reset GHC.setContext [] [] GHC.setTargets [] _ <- GHC.load GHC.LoadAllTargets return ()

I then see: # ghci-6.12.1 -package ghc t.hs GHCi, version 6.12.1: http://www.haskell.org/ghc/ :? for help Loading package ghc-prim ... linking ... done. [...] Loading package ffi-1.0 ... linking ... done. [1 of 1] Compiling Main ( dint.hs, interpreted ) Ok, modules loaded: Main. *Main> main Loading package ghc-paths-0.1.0.6 ... linking ... done. *Main> # ghci-7.0.1 -package ghc t.hs GHCi, version 7.0.1: http://www.haskell.org/ghc/ :? for help Loading package ghc-prim ... linking ... done. [...] Loading package ffi-1.0 ... linking ... done. [1 of 1] Compiling Main ( dint.hs, interpreted ) Ok, modules loaded: Main. *Main> main Loading package ghc-paths-0.1.0.8 ... linking ... done. GHCi runtime linker: fatal error: I found a duplicate definition for symbol ___stginit_ghczmprim_GHCziBool whilst processing object file /Library/Frameworks/GHC.framework/Versions/7.0.1-i386/usr/lib/ghc-7.0.1/ghc-prim-0.2.0.0/libHSghc-prim-0.2.0.0.a 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. # ghc-7.0.1 --make -package ghc t.hs [1 of 1] Compiling Main ( t.hs, t.o ) Linking t .. # ./t # (that is, no error) I'm using ghc for mac (intel 32 bits), downloaded in binary form from the ghc page. Thanks, Daniel