[Haskell-beginners] Uninstall GHC binary package? ()

[Daniel Fischer]

Am Freitag 29 Januar 2010 14:35:22 schrieb Kwanghoon Choi:
> Dear All,
>
> After I installed the ghc binary package
> (ghc-6.12.1-i386-unknown-linux.tar.bz2) manually, I can't find a way to
> uninstall it. Could anyone help me out?

It will probably be better to uninstall the 6.8.2. There are less 
antiquated GHCs in some repositories for debian based systems, you can get 
at least 6.10.* from those.

But if you really want to get rid of 6.12, I think you'll have to delete it 
manually. The most important thing is to not have the ghc, ghc-pkg, runghc 
and runhaskell scripts [perhaps some are binaries] in you /usr/local/bin [I 
suppose that's before /usr/bin in your path, hence that's picked up by 
runhaskell]. Rename them before deleting them to check whether things still 
work.

However, there's no need to get rid of either. Just learn how to use cabal-
install.

>
> Thanks in advance.
>
> Kwanghoon
>
> PS.
> I have installed two versions of ghc. One is with the ghc-6.12.1
> package, and the other is ghc-6.8.2 package. The former is downloaded to
> be installed manually, but the latter is done automatically by using APT
> tool. They are installed in a different way. I mean the ghc-6.12.1 is
> under /usr/local/bin, but ghc-6.8.2 is under /usr/bin. (Of course, you
> can change this default setting though)

apt may not be the best method to deal with Haskell stuff. With cabal-
install, you can get up-to-date versions of the packages on hackage.

>
> My original purpose is to install the newest QuickCheck package. Having
> both ghc packages seems to cause a conflict. After I try with $
> runhaskell Setup.lhs configure,

Right. "which runhaskell" will probably say /usr/local/bin/runhaskell, and

$ runhaskell --version
runghc 6.12.1

?

> I met a dependency error requiring me to
> install mtl (monad transformer library).

That is no longer included in the ghc packages.

> I did install by APT tool.

That unfortunately only knows about the 6.8.2 it installed itself, so it 
installs mtl for 6.8.2 (which, IIRC, is completely superfluous as mtl was 
still included then).

> But
> the retrial with $ runhaskell Setup.lhs configure does not work because
> the configuration is being done by ghc-6.12.1 package.

You could try

runhaskell ./Setup.lhs configure --with-compiler=/usr/bin/ghc

That would install the package for 6.8.2, if it works (which it probably 
won't because the newest QuickCheck's cabal file won't be understood by the 
old Cabal that came with 6.8.2).

> The ghc-6.12.1
> package doesn't recognize the presence of mtl package that I installed
> just before. Only the ghc-6.8.2 package seems to recognize the presence
> of mtl package. The mtl package seems to be built aligned with ghc-6.8.2
> package.

Haskell packages are built for and registered with one compiler (version) 
at the time. So 6.8.2 will know nothing about packages you register with 
6.12.1 and vice versa.

> I guess this strange phenomena comes from the different
> configuration of the two versions.
>
> This is the reason why I try to uninstall ghc-6.12.1, but it doesn't
> seem to provide any way to be uninstalled, unfortunately. If I am wrong,
> please correct me.

I suggest:

download http://hackage.haskell.org/package/cabal-install
(version 0.8, to be sure)
unpack it

cd cabal-install-0.8
./bootstrap.sh

If you get
"The 'cabal' program has been installed in ...",
all went well and you have a working cabal-install which you can use to get 
the latest greatest haskell packages (after reading the rest of 
bootstrap.sh's output and acting accordingly).

Then a simple

$ cabal install quickcheck

will download the latest quickcheck package and its dependencies, and build 
them and register them with your great 6.12.1.

If you get
"Sorry, something went wrong."
ask again here or in the haskell-cafe.