On 14 November 2012 20:35, Roman Cheplyaka <r...@ro-che.info> wrote: > * Erik Hesselink <hessel...@gmail.com> [2012-11-12 20:58:17+0100] >> And I believe the last base changes included a change to 'catch' which >> would have broken a lot of packages. The Num changes also caused a lot of >> code changes, and there were probably more I don't remember. > > Even if so, upper bounds don't prevent these errors. Cabal can't install > an older base for you. > > (I'm aware that GHC once shipped two versions of base, and dependency > bounds were actually useful then. But that's not the case nowadays, as > we see.) > > For example, here's what I get when I try to install virthualenv with > GHC 7.6.1: > > % cabal install virthualenv > Resolving dependencies... > cabal: Could not resolve dependencies: > trying: virthualenv-0.2.1 > rejecting: base-3.0.3.2, 3.0.3.1 (global constraint requires installed > instance) > rejecting: base-4.6.0.0/installed-eac... (conflict: virthualenv => > base>=4.2.0.0 && <4.6) > rejecting: base-4.6.0.0, 4.5.1.0, 4.5.0.0, 4.4.1.0, 4.4.0.0, 4.3.1.0, > 4.3.0.0, > 4.2.0.2, 4.2.0.1, 4.2.0.0, 4.1.0.0, 4.0.0.0 (global constraint requires > installed instance)
Doesn't this prevent the error of "this package won't build" (even if the error message doesn't precisely say that)? > > Roman > > _______________________________________________ > Haskell-Cafe mailing list > Haskell-Cafe@haskell.org > http://www.haskell.org/mailman/listinfo/haskell-cafe -- Ivan Lazar Miljenovic ivan.miljeno...@gmail.com http://IvanMiljenovic.wordpress.com _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe