Hi Andres, >> The new versions of mtl and transformers break many important packages, >> such as monad-par, graphviz, pandoc, and all other packages that depend >> on any of those. This situation causes serious problems for me, because >> I depend on some of those packages for my daily work. IMHO, it is an >> overreaction to have all those builds fail, because some day in the >> future a new version of Haskell Platform *may* be released that *may* >> recommend the latest versions of 'transformers' and 'mtl'. > > You make it sound like I'm inventing things. Sure, it hasn't been > released yet, and there's been some discussion about these packages in > particular. Nevertheless, it's very likely that it happens, and it's > likely that it happens this month.
obviously, there are plans to release a new version of Haskell Platform. I don't doubt that -- all I meant to emphasize is that this release hasn't happened yet. Generally speaking, there is a strong interest to conform to HP, because it provides stability and predictability. We deviate from HP only when there is a very compelling reason to do so. Another interest of ours, however, is that we want to provide a usable system, i.e. a package database that people can actually install and use. Those two interests conflict. The upcoming HP standard is probably going to mandate use of mtl 2.x and transformers 3.x -- so we have an interest in using those packages in haskellPlatformArgs_future. On the other hand, configuring GHC 7.4.1 to use those packages right now breaks a lot of other packages, some of which are extremely popular, like monad-par, graphviz, Pandoc, and everything else that depends on those. This gives us an incentive *not* to update mtl and transformers right now. Now, in order to decide whether we should update mtl today or not, we have to weigh Haskell Platform conformance against usability. > I don't think we've ever made a decision to "support" 7.4.1 already. You > seem to see this differently. Yes, exactly. I've been supporting GHC 7.4.1 for quite a while. I use it myself, and I support it in the sense that I don't commit any updates without testing first how they affect the 7.4.1 environment. I use monad-par in several of my projects, and I also heavily depend on Pandoc. The mtl update breaks those two packages, leaving me with a non-functional working environment! That situation is very unpleasant for me. Given the fact that the new HP standard hasn't been released yet, I feel that having a usable system is more important than conformance. That judgment is probably going to change once a new HP release has been made, but until then I'd rather have a system that actually works. Take care, Peter _______________________________________________ nix-dev mailing list nix-dev@lists.science.uu.nl http://lists.science.uu.nl/mailman/listinfo/nix-dev