Hi Paolo, Paolo Giarrusso wrote:
- when recompiling a package with ABI changes, does cabal always update dependent packages?
It never recompiles them. Recompilation should not be needed, because different versions of packages exports different symbols, so a package can never be linked against the wrong version of its dependency. However, see the following tickets: http://hackage.haskell.org/trac/hackage/ticket/701 http://hackage.haskell.org/trac/hackage/ticket/704
Interestingly, HTTP, directory, process, zip-archive were not reinstalled, which confirms that Cabal had reinstalled them before just because of an upgrade to the dependencies.
I think you are misinterpreting this. When you asked cabal-install to install pandoc, it tried to make a consistent install plan for all its transitive dependencies. cabal-install will not touch a package which is not a transitive dependency of the package you request to be installed. Therefore, cabal-install will not touch Cabal if you ask it to install pandoc. To make a consistent install plan, cabal-install has to pick exactly one version number for each of the transitive dependencies, so that all version constraints of all transitive dependencies are fullfilled. For some reason, cabal-install picked old-locale-1.0.0.2 instead of the already installed old-locale-1.0.0.1, and newer versions of HTTP, directory etc. too. I think this is the bug: cabal-install should not be allowed to install old-locale, because doing so apparantly causes havoc. Looking at the inter-dependencies of pandoc's transitive dependencies, I do not see a reason to install a new version of a package instead of keeping the old. Maybe it's somehow related to the transition from base-3 to base-4? But I don't know how cabal-install decides which install plan to follow anyway. Tillmann