On Saturday 11 September 2010 20:38:21, Paolo Giarrusso wrote:
Hi, after Andrew Coppin's odissey [1], I also had a few problem with cabal, which stopped installing new packages. Details will follow; meanwhile, here are some questions prompted by what happened:
- when recompiling a package with ABI changes, does cabal always update dependent packages? It seems "not always"
cabal will not automatically update packages which depend on an updated package. Since it doesn't keep a record of packages depending on foo, it would have to check all installed packages on every update to do that.
- it didn't update itself, nor refuse the breaking upgrade, and the ABI breakage caused linker errors on Setup.hs. Luckily, cabal was already linked so I could always use it for queries. - can cabal extract and check dependencies as specified in the .hi files?
No.
I had a broken dependency which I could see with "grep" but not otherwise.
ghc-pkg check?
- is there a "specification" of which are the "core" packages?
"core" as in *do not update*? Basically, what comes with GHC shouldn't be updated. Though I heard updating Cabal was okay.
Not sure if this is more useful as a bug report or as discussion, or if I just misused cabal and it's the only perfect software in the world; still I wanted to share my experience.
It's not perfect, and its guards against users breaking their package dbs aren't strong enough yet. But I wouldn't want to go back to a Haskell without it.
Also I am not sure if this is the best place - but I'm not subscribed to other lists, and the previous "cabal odissey" was posted here, so I hope it's fine.
Sure, it's about Haskell, so it's on topic here.