On 10/02/2013 21:43, Ian Lynagh wrote:
On Sun, Feb 10, 2013 at 09:30:23PM +0000, Simon Peyton-Jones wrote:
| > You may ask what use is a GHC release that doesn't cause a wave of updates? | And hence that doesn't work with at least some libraries. Well, it's a very useful | forcing function to get new features actually out and tested. | | But the way you test new features is to write programs that use them, | and programs depend on libraries.
That is of course ideal, but the ideal carries costs. A half way house is a release whose library support will be patchy.
But that's not what happens. GHC 7.8 is released. Someone installs it in order to try to use TypeHoles when developing their program. But their program depends on text, so they send Bryan a mail saying that text doesn't build with 7.8. And so the wave of updates begins.
As the maintainer of a low-level package (HTTP), I certainly see this kind of pressure starting even before a GHC release - e.g. https://github.com/haskell/HTTP/issues/36 As one of the maintainers of a high-level tool (darcs) that aims to always build against the current HP, I generate this kind of pressure myself: once GHC is released, I expect it to be in the HP within 3-6 months, so I need to get started quickly. I can't even check darcs itself until the dependencies work. I don't think there are any easy answers :-/ Ganesh