Re: HEAD can't find stg_gc_ut

One thing you can do to make this less likely to happen is to make sure 
the build system can see your .git directory, then it will give your 
build a dated version like 7.7.20121206 instead of just 7.7.  Then any 
packages you install won't clash with older ones.  Or alternatively use 
cabal-dev to install packages in a sandbox.

Cheers,
	Simon

On 06/12/12 15:17, Simon Peyton-Jones wrote:
> OK SimonM helped me past this.  Just for your info
>
> * The code generator does not actually mention stg_gc_ut; that
>    is in commented-out code.
>
> * TH was loading HSsyb-0.3.7.o, which was an old .o file created back in
>    August.  I'd just installed syb, but cabal had created libHSsyb-0.3.7.a.
>    Sadly TH ignored the new .a and took the old .o.
>
> Solution: delete the out of date .o file.
>
> Simon
>
> | -----Original Message-----
> | From: Simon Marlow [mailto:[email protected]]
> | Sent: 06 December 2012 14:41
> | To: Simon Peyton-Jones
> | Cc: [email protected]
> | Subject: Re: HEAD can't find stg_gc_ut
> |
> | It looks like you have an old syb package installed in your .cabal/lib,
> | getting rid of that should fix it.
> |
> | Cheers,
> | 	Simon
> |
> | On 06/12/12 13:53, Simon Peyton-Jones wrote:
> | > Simon, Ian, anyone
> | >
> | > I'm getting this on today's  HEAD:
> | >
> | > ~/5builds/HEAD/inplace/bin/ghc-stage2 --make T7445.hs -package syb
> | >
> | > [1 of 2] Compiling T7445a           ( T7445a.hs, T7445a.o )
> | >
> | > [2 of 2] Compiling T7445            ( T7445.hs, T7445.o )
> | >
> | > Loading package ghc-prim ... linking ... done.
> | >
> | > Loading package integer-gmp ... linking ... done.
> | >
> | > Loading package base ... linking ... done.
> | >
> | > Loading package syb-0.3.7 ... linking ... ghc-stage2:
> | > /home/simonpj/.cabal/lib/syb-0.3.7/ghc-7.7/HSsyb-*0.3.7.o: unknown
> | > symbol `stg_gc_ut'*
> | >
> | > ghc-stage2: unable to load package `syb-0.3.7'
> | >
> | > simonpj@cam-05-unx:~/tmp$
> | >
> | > Indeed, that symbol is generated in StgCmmHeap (line 631). But it
> | > doesn't seem to be defined anywhere in the RTS.  Things like stg_gc_pp
> | > are defined in Linker.c
> | >
> | > Any ideas?
> | >
> | > Simon
> | >
>