The last few days I've been thinking a bit about dependencies among our packages in HABS. My belief is that it would be beneficial to be able to very quickly see whether a set of packages is consistent in dependencies and therefore ought to compile. Now I may be wrong about this, which is why I'm asking for comments early on. I've only spent about an hour hacking on this so far, I'm confident such a tool is possible (actually rather easy) to make. So, please comment before I waste too much time on something that in fact is useless! The central part is a database of tuples: . Initially it's populated with the packages that GHC come with (base, array, etc). After that it would basically be used something like this: % pkgdb add http://hackage.haskell.org/packages/archive/dataenc/0.13.0.1/dataenc.cabal Package added, all dependencies satisfied. % pkgdb add http://hackage.haskell.org/packages/archive/dataenc/0.13.0.4/dataenc.cabal Package added, all dependencies satisfied. % pkgdb add http://hackage.haskell.org/packages/archive/nanoparsec/0.1/nanoparsec.cabal Package not added, the following dependencies not satisfied ListLike ==2.0.* base >=4.3 && <5 % pkgdb deps dataenc array >=0.1.0 && <0.4 base >=3.0.0 && <4.4 containers >=0.1.0 && <0.5 % pkgdb reqby base dataenc In short, it would make sure that the set of packages in the database is consistent at all times, and it would offer some querying functionality. Some problems: - not all CABAL files specify the complete set of dependencies (as highlighted in a few bug on cabal2arch[1]) - dependencies on non-Haskell packages isn't tracked, so it's very possible to add a package to the database that wouldn't actually compile on an Arch system because a C library is of the wrong version Possible extensions: - hooking it up to cabal2arch (e.g. by generating output that can be consumed by it) for generating PKGBUILDs and .install files So, what are your thoughts. Should I continue hacking on this? /M [1] https://github.com/archhaskell/cabal2arch/issues#issue/22 -- Magnus Therning OpenPGP: 0xAB4DFBA4 email: magnus@therning.org jabber: magnus@therning.org twitter: magthe http://therning.org/magnus