On Sun, 2009-02-01 at 01:33 -0800, Valentyn Kamyshenko wrote:
Hello all,
when I tried to install plugins package with cabal, I've got the following error:
# sudo cabal install plugins --global Resolving dependencies... cabal: dependencies conflict: ghc-6.10.1 requires process ==1.0.1.1 however process-1.0.1.1 was excluded because ghc-6.10.1 requires process ==1.0.1.0
For the most part I refer you to: http://haskell.org/pipermail/haskell-cafe/2009-January/054523.html However the difference is that you've got this problem only within the global package db rather than due to overlap in the global and user package db.
It looks like both versions of process package are currently required:
It looks like you installed process-1.0.1.1 and then rebuilt almost every other package against it. Of course you cannot rebuild the ghc package but you did rebuild some of its dependencies which is why it now depends on multiple versions of the process package. Generally rebuilding a package without also rebuilding the packages that depend on it is a bit dodgy (it can lead to linker errors or segfaults). Unfortunately cabal-install does not prevent you from shooting yourself in the foot in these circumstances.
Any suggestions?
Aim for a situation where you only have one version of the various core packages. If you do not need to install packages globally then installing them per-user means you at least cannot break the global packages. Duncan