There come patches that make darcs use Cabal 1.8.  The latter patch fixes the
excessive recompilation we have been hating since forever.

Probably in draft status, but could go in if deemed good enough.

Yours,
   Petr.

2 patches for repository darcs-unstable@darcs.net:darcs:

Tue Jan 19 19:55:33 CET 2010  Petr Rockai <me@mornfall.net>
  * Require Cabal 1.8, fix the build-deps dump in --exact-version.

Tue Jan 19 19:56:21 CET 2010  Petr Rockai <me@mornfall.net>
  * Take advantage of Cabal 1.8 internal library capability.

Attachments

• require-cabal-1_8_-fix-the-build_deps-dump-in-__exact_version_.dpatch
• unnamed

Amended to avoid conflict with Ganesh's extensible-exceptions work. A timely
review would be quite useful, as this is currently blocking the 3 of our
buildslaves that use Cabal 1.8 from building darcs. (Applying this will likely
break the others, but we can fix those by installing Cabal 1.8. I would have to
pull the 6.12 buildslave in order to avoid 1.8...)

Yours,
   Petr.

2 patches for repository darcs-unstable@darcs.net:darcs:

Tue Jan 19 19:55:33 CET 2010  Petr Rockai <me@mornfall.net>
  * Require Cabal 1.8, fix the build-deps dump in --exact-version.

Wed Jan 20 20:55:15 CET 2010  Petr Rockai <me@mornfall.net>
  * Take advantage of Cabal 1.8 internal library capability.

Attachments

• require-cabal-1_8_-fix-the-build_deps-dump-in-__exact_version_.dpatch
• unnamed

This amendment fixes witnesses and unit tests (now they work after first patch
as well after second patch).

However, it seems that it's not such a great idea to apply the second patch
just yet, as Duncan says (and I can confirm) that cabal-install does not grok
this yet. Also, he said it is broken with GHC 6.12, which is probably even
worse.

Anyway, after this iteration, at least the 1.8 bump should work.

Yours,
   Petr.

2 patches for repository darcs-unstable@darcs.net:darcs:

Wed Jan 20 22:51:58 CET 2010  Petr Rockai <me@mornfall.net>
  * Require Cabal 1.8, fix the build-deps dump in --exact-version.

Wed Jan 20 22:53:33 CET 2010  Petr Rockai <me@mornfall.net>
  * Take advantage of Cabal 1.8 internal library capability.

Attachments

• require-cabal-1_8_-fix-the-build_deps-dump-in-__exact_version_.dpatch
• unnamed

I've so far tried this on GHC 6.8.3 and 6.12.1, using cabal-install
0.8.0 built against Cabal 1.8.0.2.

6.12.1 is fine.
with 6.8.3, I had to install the Cabal 1.8.0.2 library before I could
cabal install darcs (it wasn't installed already as cabal-install was
built with a different GHC). Is there any alternative to this, like
adding Cabal 1.8 as an explicit build-dep too?

I also want to try with GHC 6.10.4 before accepting this patch, which
I'll do tomorrow night. If anyone else wants to do it in the meantime
and apply this, go ahead. Remember only to apply the first patch.

I've created http://hackage.haskell.org/trac/hackage/ticket/634 for the
cabal-install issue.  

I'd like to wait maybe one week (till 21 Feb) to see if the Cabal folks
can tell us if (A) this will be fixed by Darcs 2.5 (July 2010?) and (B)
if this will be fixed any sooner than that.

If we don't hear back from them by next week, we should make a decision
about how to move forward.  I've been polling the Review Team about this
(still need to ask/hear from Trent and Reinier).  If we don't reach a
consensus, I can make any one of these Iron Fist decisions to unblock
things.  It sounds like nobody is really that bothered either way, so
it'll really just be a very lightly plated fist.

(we may need a new 'blocked' patchstatus)

It doesn't look like the cabal team has reviewed the ticket Eric 
created.

Eric, what is the next step?

Thanks,
Jason

Thanks for the patch management.  The next step is to see if Duncan can
be persuaded to work on this during ZuriHac :-)

Here's the current progress on this.  Duncan has fixed hackage #634 (and
more importantly) the GHC 6.12 support for this.  Progress!

Looks like our next job is to (a) wait for the releases of Cabal and
cabal-install respectively and (b1) bump the Cabal version requirement
on darcs.cabal or (b2) wait for the next point release of the GHC 6.12
Haskell Platform to be released.

Either way, we can afford to wait, because it turns out I was wrong
about this blocking other work.

Using amend-in-progress.  Maybe we need a patchstatus to mean
waiting-for-precondition

This has been fixed in cabal-install 0.8.2, but it'll take a while until 
it gets widespread-enough for us to require it, I guess. The patch is 
also woefully out of date. If there's still demand for this, someone will 
need to do the .cabal changes again, I think.