Re: [arch-haskell] help upgrading packages

On 2014-05-15 11:35, Magnus Therning wrote:

On Wed, May 14, 2014 at 10:47 PM, Bardur Arantsson wrote:

...

On 2014-05-12 15:47, Magnus Therning wrote: [--snip--]

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?

You *do* need to keep the sandbox around (or at least parts of it). That's where the last "cabal install" line installs to.

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.

If you want to use a sandboxed thing as a library then you need to develop "inside" the sandbox, so e.g. you'd just create a little cabal file for your project which declares all the dependencies and use cabal to build your project.

...

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.

Cabal also works beautifully for "hobby" type development. Once you've created a cabal file you hardly ever need to touch it again. :) Regards,