draft proposal on provenance-qualified dependencies

[Gershom B]

I've updated the proposal with increased motivation as suggested, and
submitted it to the repo.

Here is the discussion thread:

https://github.com/ghc-proposals/ghc-proposals/pull/115

--g

On Fri, Feb 23, 2018 at 11:03 AM, Simon Peyton Jones
<simonpj at microsoft.com> wrote:
> |  current existing "search path-like" functionality where a chain of
> |  overlays may live over a repo. The proposal does not address that,
> |  because it is how things work already -- although arguably, the way in
> |  which this works may be insufficiently understood among existing cabal
> |  users?
>
> Well I can say with certainty that it's insufficiently understood by /this/ cabal user.
>
> I had no idea there could be more than one repo, which 'cabal update' caches locally.
>
> Simon
>
> |  -----Original Message-----
> |  From: Gershom B [mailto:gershomb at gmail.com]
> |  Sent: 23 February 2018 15:02
> |  To: Simon Peyton Jones <simonpj at microsoft.com>
> |  Cc: cabal-devel <cabal-devel at haskell.org>
> |  Subject: Re: draft proposal on provenance-qualified dependencies
> |
> |  Thanks for these comments Simon. It is good to have a sanity-check on
> |  these proposals before they go before a broad audience. I'll try to
> |  take them into account and submit this properly as a proposal
> |  (including creating the associated discussion thread) in the next few
> |  days. If anyone else has any thoughts (bear in mind this involves
> |  cross-cutting changes across cabal files and a bit of ghc) please send
> |  them on.
> |
> |  On "Does a particular build have to use packages from one repo only?"
> |  -- the idea is that _per package_ a provenance may be specified to a
> |  specific repo. If no provenance is specified, then there is the
> |  current existing "search path-like" functionality where a chain of
> |  overlays may live over a repo. The proposal does not address that,
> |  because it is how things work already -- although arguably, the way in
> |  which this works may be insufficiently understood among existing cabal
> |  users? (In fact, looking at the cabal documentation, I see that the
> |  description of multiple remote repos doesn't specify the manner in
> |  which they are combined, which it should).
> |
> |  Cheers,
> |  Gershom
> |
> |  On Fri, Feb 23, 2018 at 6:26 AM, Simon Peyton Jones
> |  <simonpj at microsoft.com> wrote:
> |  > Gershom
> |  >
> |  > Looks like a great idea.
> |  >
> |  > Lots of questions though:
> |  >
> |  >
> |  > - I think more motivation would be helpful.  E.g. "You are in change
> |  >   of the GHC 8.6 release.  Package authors don't want to upload a
> |  new
> |  >   version of their packages until 8.6 is out, but you still want to
> |  >   smoke-test 8.6 against their packages.  Doing so requires some
> |  minor
> |  >   changes (version bounds, changes in base-library APIs etc); so you
> |  >   want to be able to make these changes in a sandbox that won't hurt
> |  >   anyone".      Or something like that.
> |  >
> |  >   Maybe describe other use-cases.  It's *much* easier to evaluate
> |  >   a proposal when I'm totally clear what it's for.
> |  >
> |  > - Does a particular build have to use packages from one repo only?
> |  >   Or is there something like a "search path"?
> |  >
> |  > Thanks!
> |  >
> |  > Simon
> |  >
> |  > |  -----Original Message-----
> |  > |  From: cabal-devel [mailto:cabal-devel-bounces at haskell.org] On
> |  > | Behalf  Of Gershom B
> |  > |  Sent: 19 February 2018 00:26
> |  > |  To: cabal-devel <cabal-devel at haskell.org>
> |  > |  Subject: draft proposal on provenance-qualified dependencies
> |  > |
> |  > |  Hey all, I mentioned (on the long SLURP thread) that I was
> |  thinking
> |  > | about a general proposal for provenance-qualified dependencies to
> |  > | reduce coupling in the haskell ecosystem. Having worked it out a
> |  > | bit,  I think the bigger win is it also provides a way to specify
> |  > | dependencies on git repos, etc., which has been an oft-requested
> |  > | feature.
> |  > |
> |  > |  I don't want to submit it as an ecosystem proposal proper without
> |  > | further polish, and I held off on bugging a larger audience of
> |  cabal
> |  > | folks until the 2.2 branch was cut. So now I'm passing this along
> |  > | for  further comment and polish before I make a real proposal:
> |  > |
> |  > |
> |  https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit
> |  > | hu
> |  > |  b.com%2Fgbaz%2Fghc-proposals%2Fblob%2Fpatch-1%2Fproposals%2F0000-
> |  > |  provenance-qualified-
> |  > |
> |  > |
> |  imports.rst&data=04%7C01%7Csimonpj%40microsoft.com%7C64fd20012b9a4b2
> |  > | 4d
> |  > |
> |  > |
> |  28508d5772f6cf2%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C6365459
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> |  936143539%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMz
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> |  > |  LCJBTiI6Ik1haWwifQ%3D%3D%7C-
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> |  1&sdata=cH0gNADmzA%2BTkmXZEDY6lLYUTx2D2KX%2B3T8KO%2FvU86s%3D&reserve
> |  > | d=
> |  > |  0
> |  > |
> |  > |  There's no urgency, but it would be good to get some feedback in
> |  > | the  next few weeks if possible.
> |  > |
> |  > |  Cheers,
> |  > |  Gershom
> |  > |  _______________________________________________
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> |  > |  askell.org%2Fcgi-bin%2Fmailman%2Flistinfo%2Fcabal-
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