id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc	os	architecture	failure	difficulty	testcase	blockedby	blocking	related
3951	Unknown symbol error when ghci tries to load package scion	greenrd		"If you add scion to your flags in ~/.cabal/config, and then do the following:

{{{
git clone git://github.com/greenrd/scion.git
cd scion
git checkout devel   # DON'T OMIT THIS LINE!!!
cabal install
cd ..
darcs get --lazy http://code.haskell.org/yi/
cd yi
}}}

and then make the following change to yi.cabal

{{{
           -- requires an unreleased version atm.
 
         if flag (scion)
-          build-depends: ghc == 6.10.*
+          build-depends: ghc >= 6.10.1
           build-depends: ghc-syb
           build-depends: scion
           cpp-options: -DSCION
}}}

and then do cabal install, you should get, after some time, when it gets around to compiling yi itself:

{{{
Loading package multiset-0.2 ... linking ... done.
Loading package network-bytestring-0.1.2.1 ... linking ... done.
Loading package uniplate-1.4 ... linking ... done.
ghc: /home/greenrd/.cabal/lib/scion-0.1.0.3/ghc-6.12.1/HSscion-0.1.0.3.o: unknown symbol `scionzm0zi1zi0zi3_ScionziTypesziOutline_OutlineDef_con_info'
Loading package scion-0.1.0.3 ... linking ... ghc: unable to load package `scion-0.1.0.3'
cabal: Error: some packages failed to install:
yi-0.6.2.2 failed during the building phase. The exception was:
ExitFailure 1
}}}

(I had to make a couple of changes from upstream scion to make scion compile together with yi, and those are in my repository.)

Although, to save time, you probably DON'T need to go to the trouble of trying to compile yi - I'd hazard a guess that the bug occurs in the compilation of scion, not the compilation of yi.

I did ""cabal clean"" in the scion directory and tried again - same result."	bug	closed	normal	6.12.3	Compiler	6.12.1	invalid			Linux	x86	None/Unknown