Themes for 1.22

Thu Apr 24 12:10:05 UTC 2014

I will definitely look into that! Thank you. The one your that does force
you down though is the path only developing against releases, and even
those are light-weight internal patch releases to your own hackage it still
means a longer compile-test cycle. Maybe if that's a problem it indicates
that my package boundaries are too fine, but I find add-source to be
invaluable, I would find it even nicer if it was a little bit more first
class. If you look at how source dependencies are covered in VS when
programming in .Net, that's somewhat how I would like to see it managed in
cabal. It's trivial to have common assemblies in a source tree shared
between projects.

Ben

On Thu Apr 24 2014 at 12:50:45, Erik Hesselink <hesselink at gmail.com> wrote:

> You can handle this scenario pretty easily by setting up a private
> hackage. Then add a second remote-repo to your cabal config, either
> globally or in the sandbox. We do this, and it works pretty well.
>
> Regards,
>
> Erik
>
> On Thu, Apr 24, 2014 at 1:33 PM, Benjamin Edwards
> <edwards.benj at gmail.com> wrote:
> > Hi Johan,
> >
> > Not sure if this mail is a request for comments, but on the story for
> large
> > projects one thing that I would like to see is the ability to add
> packages
> > that aren't in hackage to the depends list. I agree that adding some
> > scanning and auto add ability is definitely sorely needed, but this
> > information goes into add-source-timestamps in the sandbox folder, and if
> > you blow away the sandbox, it's gone. Or you can try and version a file
> that
> > contains ever changing timestamps. Right now I have a shell script that
> > maintains a list of added sources and I keep that versioned in the
> project.
> > It would be nice to have git dependencies in there as well, and then
> > disallow a hackage upload for any cabal file with a non-hackage
> dependency
> > listed. I would be happy to contribute time to both design and
> > implementation.
> >
> > Ben
> >
> > On Thu Apr 24 2014 at 10:53:59, Johan Tibell <johan.tibell at gmail.com>
> wrote:
> >>
> >> Hi all,
> >>
> >> While I'm sure we still have a bugfix release or two to make on the 1.20
> >> branch, I thought it'd be worth looking at what we want to accomplish
> for
> >> 1.22. Here are my thoughts on what we should focus on:
> >>
> >> ## A dependency solver that always works
> >>
> >> As Hackage has grown so have the requirements of the dependency solver.
> >> There are three distinct problems I'm seeing now that we should tackle:
> >>
> >>  * Treat each sections (i.e. library, test suite, benchmark, and
> >> executable) in the .cabal file separately for the purpose of dependency
> >> resolution. Today all the sections' dependencies are merged and used as
> the
> >> constraints of the package as a whole. This is troublesome for all
> packages
> >> that are dependencies of QC, HUnit, test-framework, and criterion, as
> >> there's a dependency cycle if you treat e.g. the containers package and
> its
> >> test suite as one unit.
> >>
> >>    The solution here is to treat each unit as a mini package for the
> >> purpose of dependency resolution. This would also allow you to have e.g.
> >> several executables with conflicting dependencies.
> >>
> >>  * Improve performance. Some packages (e.g. yesod) can take over 10
> >> seconds to run over. This problem will get worse as Hackage grows and we
> >> build bigger applications on top of it, so we need to tackle this now
> before
> >> it becomes a real problem.
> >>
> >>  * Fix Hackage package blacklisting. Users can blacklist packages on
> >> Hackage e.g. if they know them to be broken. However, this doesn't
> really
> >> work as the Hackage blacklist translates to a soft preference in the
> >> dependency solver and is thus often ignored. See
> >> https://github.com/haskell/cabal/issues/1792 for the gory details.
> >>
> >> ## Do the right thing automatically
> >>
> >> This is a carry-over from the 1.20 goals, as we didn't make much
> progress
> >> here.
> >>
> >> The focus here should be on avoiding manual steps the cabal could do
> >> for the user.
> >>
> >>  * Automatically install dependencies when needed. When `cabal build`
> >> would fail due to a missing dependency, just install this dependency
> >> instead of bugging the user to do it. This will probably have to be
> >> limited to sandboxes where we can't break the user's system
> >>
> >>  * GHCi support could be improved by rebinding :reload to rerun e.g.
> >> preprocessors automatically. This would enable the users to develop
> >> completely from within ghci (i.e. faster edit-save-type-error cycle).
> >> We have most of what we need here (i.e. GHC macro support) but someone
> >> needs to make the final change to generate a .ghci file to pass in the
> >> ghci invocation.
> >>
> >> ## Faster builds
> >>
> >> I think we're almost done here. There's really only one remaining thing
> to
> >> do:
> >>
> >>  * Build components and different ways (e.g. profiling) in parallel.
> >> We could build both profiling and non-profiling versions in parallel.
> >> We could also build e.g. all test suites in parallel. The key
> >> challenge here is to coordinate all parallel jobs so we don't spawn
> >> too many.
> >>
> >> ## Support large projects
> >>
> >> This is also a carry-over from the 1.20 goals.
> >>
> >> We still don't have a good story for large projects. Sandboxes are too
> >> annoying to use if there are 100 add-source deps. We need more
> automation
> >> and more opinionated defaults (e.g. scan the sub-directories from in
> which
> >> cabal was run to find source packages.)
> >>
> >> What we need most of all here is a design. Perhaps we could try to get
> >> together at some Hackathon/ICFP and discuss.
> >>
> >> ## Issue tracker spring cleaning and test suite improvements
> >>
> >> The issue tracker is out-of-hand. It's too unwieldy to use for planning
> >> our work and get an overview of the most important issues. We should
> try to
> >> close down bugs that haven't had updates in years with extreme
> prejudice. If
> >> the issue is important it will pop up again.
> >>
> >> We're also severely lacking in the testing department. There are two
> >> problems:
> >>
> >>  * There aren't enough tests: the cabal user facing surface is quite
> >> larger (lots of features and flags) and many of them are not tested at
> all,
> >> which will lead to regressions as we keep fixing bugs and adding
> features.
> >>
> >>  * The tests take too long to run: we have too many end-to-end style
> tests
> >> (i.e. build a whole package) and not enough unit style tests. We need
> to add
> >> more of the latter kind.
> >>
> >> Cheers,
> >>   Johan
> >>
> >> _______________________________________________
> >> cabal-devel mailing list
> >> cabal-devel at haskell.org
> >> http://www.haskell.org/mailman/listinfo/cabal-devel
> >
> >
> > _______________________________________________
> > cabal-devel mailing list
> > cabal-devel at haskell.org
> > http://www.haskell.org/mailman/listinfo/cabal-devel
> >
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.haskell.org/pipermail/cabal-devel/attachments/20140424/9fbdc15d/attachment.html>