Hackage rocks

[Duncan Coutts]

Yes indeed, Hackage rocks.

Henning Günther wrote a Hackage -> Gentoo ebuild conversion tool for us
and that allowed us to import more than 50 new packages into the Gentoo
Haskell overlay.

So we now have more than 150 packages available in the overlay, with a
subset of 50 in the main Gentoo portage tree.

This kind of productivity would have been impossible previously.

So with that number of packages available we should be able to give a QA
perspective. I've not checked exhaustively but here's my impression of
common issues:

      * haddock docs not building. This is very common. The most common
        parse problem is un-escaped / chars. This seems to trip people
        up a lot. I wonder if we could make haddock's parser grok this
        better? For example most uses of ' don't cause problems, eg
        "don't". I wonder if we could have a similar rule for / so that
        things like "I/O" didn't get recognised as beginning an
        emphasised section. Perhaps the rule should be that / but be at
        the beginning or end of a token, so a " / " or a "X/Y" would not
        count, only "/beginning" or "ends/" of words?
      * packages not building with later versions of dependent packages.
        Eg changes in what modules are re-exported by some mtl modules
        between mtl-1.0 and 1.0.1.
      * inability to automatically find/generate dependencies on
        external packages like C libraries. Many packages that use FFI
        need to link to non-standard C libs and it's not always obvious
        what packages they need. Of course, specifying external libs is
        not simple since different platforms often call them different
        things, but perhaps we could have some non-binding hint fields.
        Or perhaps we should just try and guess based on the names of
        the libs that need to be linked to (though that doesn't cover
        deps on other programs rather than C libs).

Duncan