On Sat, Jul 25, 2009 at 11:25:12PM -0700, Donald Bruce Stewart wrote:
johan.tibell:
In general, I think it would be a good idea to provide some statistics of how many packages would break as the result of a backwards incompatible change.
Agreed. And it should be required as part of release processes for GHC.
Duncan has described the process of building large amounts of Hackage,
http://blog.well-typed.com/2009/03/regression-testing-with-hackage/
That process requires too much effort. IIRC it took more than a day of actual human time to get the package list set up etc, and requires you to make some non-obvious decisions along the way. I think a better process would be more along the lines of: for p in $packages cabal install p rollback? except smarter, so that it doesn't try to install packages that it has already installed as a dependency of something else. Thanks Ian