Maciej Piechotka schrieb: > On Wed, 2010-05-05 at 01:09 +0200, Daniel Fischer wrote: >> On Mittwoch 05 Mai 2010 00:55:38, Maciej Piechotka wrote: >>> I try to configure happstack with parsec 3.1. It seems to fail due to >>> cabal: >>> >> happstack-util.cabal says parsec < 3, so --constraint="parsec > 3" and the >> given dependencies are incompatible, hence it can't be configured. >> >> Probably parsec < 3 was specified because parsec-3.0 was significantly >> slower than parsec-2.*. > > I updated local copy, as shown, but cabal wants to rebuild it anyway. My > question was rather why the repo is considered at all when the package > is installed.
Surprisingly using plain Cabal (runhaskell Setup configure; runhaskell Setup build; runhaskell Setup install) often works in these cases. Cabal-install is somehow too clever and if it cannot resolve the dependencies it thinks this must be impossible. If it finds a package, that it could not have installed by itself, it tries to install it by itself. First I thought that this due to cabal-install trying to find appropriate flag assignments by itself. However, Duncan Coutts told me that plain Cabal tries this as well. I have no idea, what the key difference between cabal-install and plain Cabal is. _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe