#951: Incorrect error messages for non-existing dependencies ---------------------------------+------------------------------------------ Reporter: guest | Owner: Type: enhancement | Status: new Priority: normal | Milestone: cabal-install-0.16 Component: cabal-install tool | Version: 1.14.0 Severity: normal | Keywords: message, solver Difficulty: unknown | Ghcversion: 7.4.1 Platform: Linux | ---------------------------------+------------------------------------------ Changes (by kosmikus): * keywords: message solver => message, solver * type: defect => enhancement * milestone: => cabal-install-0.16 Comment: Thanks for the report. I'm not sure what you would actually expect here. The solver has some freedom in which order to try to resolve the goals. And the problem it reports is the first problem it hits. The presence of the bogus dependency in this case prevents the solver from successfully backtracking. So yes, there's more than one problem in this case, and in general, it's difficult to judge which one's the one you want to hear about. If you remove the bogus dependency, it will still run into the problem you show above at first, but continue backtracking, and will ultimately find a solution (probably by picking an older version of transformers). So I agree that this might not be the error message you expect, and I see it as a valid enhancement request. But the error message given isn't "incorrect", and I unfortunately don't see a clear heuristics to apply here. -- Ticket URL: http://hackage.haskell.org/trac/hackage/ticket/951#comment:1 Hackage http://haskell.org/cabal/ Hackage: Cabal and related projects