[Haskell-cafe] One problem with Cabal-install and dependencies

[Michael Lazarev]

Ivan Lazar Miljenovic wrote:

> You don't install containers by hand.

I didn't want to, I had to do this because one library depending on
them ceased to install.

> This package sounds a bit like the package you're trying to install
> hasn't been updated to the latest version of GHC (containers-0.2 was
> GHC-6.10, wasn't it?).

On http://hackage.haskell.org/package/containers-0.2.0.1 it is stated
that it's "Built on: ghc-6.12"

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Daniel Fischer wrote:

> containers-0.2.0.1 (reinstall) changes: base-4.1.0.0 -> 3.0.3.1
>
> And it's pretty adamant about the last line.
>
> Try containers-0.2.0.0, cabal-install doesn't announce to ignore the base-
> constraint for that one.

Alas, with ghc-6.12.2, I had the same error for containers-0.2.0.0

> containers-0.2.0.1 doesn't give an upper bound for the base version, so
> cabal-install chooses base-3 by default (less likely to break on older
> packages than the still more reduced base-4).

Do you mean that if it's just "build-depends: base" without version
constraint, cabal-install has some special code that chooses the third
version of base?

I'd like to note that I finally managed to install the package after
changing "build-depends: base, array" to "build-depends: base == 4.*,
array" in containers.cabal file. Thanks for some pointers.