Jeremy Shaw
I don't really see this listed on your list, but maybe I missed it.
Happstack has been affected by QuickCheck 1 -> QuickCheck 2, parsec 2 -> 3, and HaXml 1.13 -> 1.20.
Those packages are common, and people often want to use happstack with other libraries that also use those packages. The problem is that if we upgrade to the newer versions, then people can't use happstack with libraries that use the old version. For example, when we upgrade to QuickCheck 2, gitit no longer installed, because some dependency of gitit still used (and perhap still does) QuickCheck 1.
My understanding is that this is caused by a limitation in ghc-pkg which can't tell the difference between re-exposed and only-used-internally dependencies. I recall having a discussion with either you or someone else from the happstack team about why it isn't applicable there, but the QuickCheck problem can be solved in the general case by having its dependency be a compile-time-only option which is disabled by default. However, this is definitely a major problem with parsec, HaXml, etc. and probably what I consider the main argument _against_ keeping the same name for fgl, though this can occur with packages even with a relatively minor API change (e.g. haskell-src-exts going from 1.6 to 1.7; the API change was minor but until all package maintainers upgraded their packages to work with 1.7 there would be some inconsistencies). -- Ivan Lazar Miljenovic Ivan.Miljenovic@gmail.com IvanMiljenovic.wordpress.com