[Haskell-cafe] technical thoughts on stack

[Paolo Giarrusso]

On Tuesday, September 13, 2016 at 10:05:44 PM UTC+2, Christopher Allen 
wrote:
>
> Stack users are moving away from enabling system installed GHCs by
> default because it breaks the ease of enabling profiling for libraries
> when you're using a Stack-installed GHC.

 

> I'm not sure why multiple system-installed GHCs needs to be supported
> in addition to the GHC support Stack already provides. That's extra
> work for...what? Stack isn't trying to compete with Nix. It's more
> like a blend of rustup and cargo -- or Clojure's Leiningen.
>

To clarify: I'm not proposing stack to install those GHCs, just to use them.

I think the extra work would be limited (calling GHC-X.Y.Z instead of GHC) 
and has other technical advantages 
(https://github.com/commercialhaskell/stack/issues/2433). Mind you, I'm 
willing to contribute the work and not asking anybody—I've just been busy.

Right now I have to modify the PATH every time I use GHC 7.8.4 because I 
needed to customize the build (I'm on OS X 10.11), but I still want GHC 8 
by default.
 

> On Tue, Sep 13, 2016 at 3:01 PM, Paolo Giarrusso <p.gia... at gmail.com 
> <javascript:>> wrote:
> >
> >
> > On Tuesday, September 13, 2016 at 9:47:20 PM UTC+2, Richard Eisenberg 
> wrote:
> >>
> >> Thanks, many, for explaining better ways to interact directly with GHC
> >> after using a `stack setup`. Perhaps, then, all that’s stopping someone 
> like
> >> me from liking the ease of `stack setup` is a little missing PR (as in,
> >> public relations). I understand that many people want to keep GHC 
> cloistered
> >> away to ease version swapping, but others (like me) want GHC available 
> front
> >> and center.
> >>
> >> Other minor points:
> >> `stack env` does not work for me: my version of stack does not know how 
> to
> >> `env`.
> >
> >
> > That's correct—stack env was a feature request.
> >
> > The warning on `stack ghci` doesn't happen usually, but I'd say that's a 
> bug
> > (probably because it's a new install)?
> >
> > I use stack (and have contributed a bit recently), but I agree there's a 
> few
> > things stack could do better for this workflow.
> >
> > And the transition has a rather annoying learning curve—stack ghci and 
> stack
> > ghc are not the same as ghci/ghc. I think that's on purpose to support a
> > project-based workflow, and it has upsides, but it's a transition 
> pitfall.
> >  Lots of things *are* explained in
> > https://docs.haskellstack.org/en/latest/faq/, but you do need learn a 
> few
> > things from scratch.
> >
> > You want stack exec ghc and stack exec ghci, and arbitrary options 
> require a
> > double dash `--` — use `stack ghc -- --version` or `stack exec -- ghc
> > --version`. And I'm afraid the command syntax is mostly frozen by now.
> >
> > To support a compiler-based workflow, there are a few things planned—I
> > opened an issue to collect them, starting from Simon Marlow's recent 
> email:
> > https://github.com/commercialhaskell/stack/issues/2546
> >
> > BTW, a system-installed GHC already works if you stick to one (and only
> > build projects that need that). But I'd love to support multiple
> > system-installed GHCs and being able to pick the one you need.
> >
> > As others already explained, giving access to stack-installed GHCs can be
> > problematic—they're going to work, in part, exactly because you can't
> > install in their package database.
> >
> > Having stack install system-wide GHCs would IMHO risk opening a can of
> > worms—having working binaries for all Linux distros requires some work,
> > system installers would be harder and most users would dislike them.
> >
> > _______________________________________________
> > Haskell-Cafe mailing list
> > To (un)subscribe, modify options or view archives go to:
> > http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe
> > Only members subscribed via the mailman list are allowed to post.
>
> -- 
> Chris Allen
> Currently working on http://haskellbook.com
> _______________________________________________
> Haskell-Cafe mailing list
> To (un)subscribe, modify options or view archives go to:
> http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe
> Only members subscribed via the mailman list are allowed to post.
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.haskell.org/pipermail/haskell-cafe/attachments/20160913/ad92d57b/attachment.html>