Cabal woes

[Brandon Allbery]

Mikhail, the use case not addressed here is people who are used to v1-style
and want to keep using it — and possibly aren't in a great position to
rewire their setup to fit how v2 thinks. Personally, I have situations
where I use v2 and others where v1 works better.

On Mon, Apr 15, 2019 at 6:43 PM Mikhail Glushenkov <
mikhail.glushenkov at gmail.com> wrote:

> Hello Simon,
>
> On Mon, 15 Apr 2019 at 23:14, Simon Peyton Jones via ghc-devs
> <ghc-devs at haskell.org> wrote:
> >
> > It is terribly mysterious that “cabal install hspec” doesn’t, well,
> install hspec.
>
> In the cabal v2-* model [1] installing libraries globally is no longer
> the recommended mode of operation, which is why you now need to pass
> --lib to 'install' to do that.
>
> There are now better alternatives for most use cases of 'install --lib':
>
> * For just trying out some set of libraries in REPL, you can use
> `cabal new-repl --build-depends=foo,bar,baz` outside of a project
> instead of ghci. [2] If you have .ghc.environment file generation
> turned on, you can also use plain ghci inside your project, and it
> will pick up the project context. [3]
> * For running Haskell scripts that expect extra libraries in the
> global package DB you can use `#! cabal` instead of `#! runghc`. [4]
>
> > It must surely be a bug that “cabal install –lib hspec” simply crashes.
>
> This is a bug that we haven't fixed yet [5]. Should've just worked.
>
>
> [1] https://cabal.readthedocs.io/en/latest/nix-local-build-overview.html
> [2]
> https://cabal.readthedocs.io/en/latest/nix-local-build.html#cabal-v2-repl
> [3]
> https://cabal.readthedocs.io/en/latest/nix-local-build.html#cfg-field-write-ghc-environment-files
> [4]
> https://cabal.readthedocs.io/en/latest/nix-local-build.html#cabal-v2-run
> [5] https://github.com/haskell/cabal/issues/5990
>


-- 
brandon s allbery kf8nh
allbery.b at gmail.com
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.haskell.org/pipermail/ghc-devs/attachments/20190415/3e688114/attachment.html>