Hi everyone, I'm working on some improvements to 'cabal init', the biggest of which is looking at imports in source files to guess an initial list of dependencies to populate the 'Build-depends:' field. I wanted to get some feedback on a design decision: what to do when we find multiple packages providing the same module? Suppose we find a source file with the line import Foo.Bar So we get the list of installed packages, and look for packages providing the Foo.Bar module. If there's only one, great! We just use that version of that package as a dependency (with a conservative upper bound guided by the PVP). However, I suspect that much of the time we will instead find something like this: Scenario A: foobar-0.3 foobar-0.4 foobar-0.4.1 Scenario B: foobar-0.3 wizbang-0.4 all providing Foo.Bar. In Scenario A, which do we pick as our dependency: (a) foobar >= 0.3 && < 0.5 (b) foobar >= 0.4 && < 0.5 (c) foobar >= 0.4.1 && < 0.5 Personally, I lean towards (b): the earliest version PVP-compatible with the latest available version. But I could in principle be convinced of any of these options. In Scenario B, do we: (a) arbitrarily pick a package (and generate a warning) (b) refuse to pick either package (and generate a warning)? (c) pick *both* and let the user clean up the mess later (and generate a warning)? I suppose (b) seems most sensible. It's possible no one really cares and it doesn't matter that much, which is also fine. =) -Brent