[Haskell-cafe] Re: 1,000 packages, so let's build a few!

[Duncan Coutts]

On Mon, 2009-02-02 at 08:29 -0800, Don Stewart wrote:
> jwlato:
> > Duncan Coutts wrote:
> > >
> > > Some are trivial and should be done away with. For example the ones that
> > > just check if a C header / lib is present are unnecessary (and typically
> > > do not work correctly). The next point release of Cabal can do these
> > > checks automatically, eg:
> > >
> > >        Configuring foo-1.0...
> > >        cabal: Missing dependencies on foreign libraries:
> > >        * Missing header file: foo.h
> > >        * Missing C libraries: foo, bar, baz
> > >        This problem can usually be solved by installing the system
> > >        packages that provide these libraries (you may need the "-dev"
> > >        versions). If the libraries are already installed but in a
> > >        non-standard location then you can use the flags
> > >        --extra-include-dirs= and --extra-lib-dirs= to specify where
> > >        they are.
> > 
> > Thank you!  Thank you!  Thank you!
> > 
> > For those of us who want to write cross-platform (i.e. Windows)
> > bindings to C libraries, this is great news.
> 
> It will be important now to report the lack of uses of these portability
> tests back to the authors of packages.

Note that to get the above checks authors don't have to do anything
except list the C libs in the extra-libraries field as normal. No
Setup.hs code or ./configure scripts are required (though it should work
with packages that do use ./configure scripts).

> A start would be to have hackage warn, I suppose.

I'm not quite sure what we can warn about here except the general use of
configure scripts (which is not a good idea at least at the moment). We
need to work out what everone is using them for first:
http://hackage.haskell.org/trac/hackage/ticket/482

Duncan