[Haskell-cafe] GHC 6.12 on OS X 10.5

[Duncan Coutts]

On Mon, 2009-12-21 at 10:32 +0000, Conor McBride wrote:

> QUESTION: Is the sensible upgrade path to build cabal-install 0.8 with
> your old GHC, before installing 6.12? Does this even work?

Yes and yes.

> Anyhow, I've got 6.12 and I need cabal-install 0.8. Can I find it?

Note that it is now on hackage, though it may not have been when you
first looked. There was a window of a few days between the ghc-6.12.1
and cabal-instal-0.8.0 releases.

> I tried installing parsec with runhaskell Setup.hs
> {configure,build,install} but each of these commands appeared content
> to do precisely nothing: I found this perplexing.

That's fairly odd. Sounds like it might be worth reporting. Perhaps
runhaskell is borked.

> I tried reverting to 6.10.4 and compiling cabal-install. This made
> more progress, but died with some sort of zlib version snafu. (I'm
> sorry, I should have recorded the details but didn't.) The
> zlib-0.5.2.0 package did install successfully, but somehow the build
> for cabal-install itself went awry with an "even though this is the
> right version I can't find X" sort of a problem.

I know of some problems people bump into with zlib on OSX but this
doesn't immediately match any of them. If you can reproduce this I'd be
interested to know.

For reference, the most common one is that people on OSX 10.6 have
hacked their ghc wrapper script to build 32bit binaries but not realised
they need to do the same for hsc2hs, and then zlib is the first FFI
package they build after that.


> I worry about this.
>    (1) What have I broken by shifting the opt/local/lib copy of  
> libiconv?

Likely, all the programs installed via macports that depend indirectly
on iconv.

>    (2) Why did that break things anyway?

Because the macports iconv and the system ones are not compatible. The
ghc base lib is built against the system one, but if /opt/local/lib ends
up on the linker path for whatever reason then when ghc links a program,
the linker will pick up the macports iconv and that of course will fail
to link.

>    (3) How come I ended up with a broken library setup?

Not quite sure what you mean.

>    (4) What else is broken? (What's worse than finding a maggot in your
>         apple? Finding half a maggot in your apple.)

Probably just all the progs installed via macports.


Duncan