[arch-haskell] help upgrading packages

[Magnus Therning]

On Wed, May 14, 2014 at 10:47 PM, Bardur Arantsson <spam at scientician.net> wrote:
> On 2014-05-12 15:47, Magnus Therning wrote:
> [--snip--]
>> The same goes for me.  Occasionally I revert to installing a package
>> for the local user only, but not even then do I use `cabal install` to
>> do that, I prefer running `./Setup.hs configure,build,install` myself.
>>
>> I do mean to look into using `cabal` myself at some point, because I
>> keep on hearing good things about it.  So far every time I've tried it
>> I've run into something weird, most recently it was trying to install
>> an older version of a lib than was needed, and I already had the newer
>> version installed on my system too.  A lot of terrifyingly clever
>> people swear by it though, so there has to be something I'm missing
>> out on!
>
> Gah! Just try it!
>
> All I needed to install build-wrapper (which I think was the inital
> "problem" package in this thread) was to do
>
> $ mkdir somewhere/buildwrapper
> $ cd somewhere/buildwrapper
> $ cabal sandbox init
> $ cabal install buildwrapper
>
> Add "somewhere/buildwrapper" to $PATH. Bonus points for using "stow" or
> similar.
> The key point in the above recipe is to *NOT* have all kinds of
> libraries installed system-wide (aka. via pacman). It usually works
> better that way.

Surely you should then `cabal install` the tool so you don't end up
with a complete sandbox with every dependency of buildwrapper's in it,
no?

For some packages you would have to keep the sandbox around and do it
your way though, e.g. `pandoc` since it contains both a library and
executables.

> Disclaimer: I haven't actually used buildwrapper personally, but one
> assumes that it just acts as an executable and doesn't install things
> into its own environment or other weird things.

Personally I think `cabal` really shines when doing more serious
Haskell development than I do.  I never test my Haskell packages on
anything other than the GHC that's in [haskell-core], and neither do I
test them against any other versions of packages than what's found in
[haskell-core].  My Haskell development is completely in my free time
and for fun.  I think that if I ever am lucky enough find myself using
Haskell professionally I'd quickly see more use in what `cabal` has to
offer.

/M

-- 
Magnus Therning                      OpenPGP: 0xAB4DFBA4
email: magnus at therning.org   jabber: magnus at therning.org
twitter: magthe               http://therning.org/magnus