Simon Marlow wrote:

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I suggest if we stick with the independent repo approach that we have some automation to check that changes are indeed getting pushed upstream.

Agreed. Can you think of an easy way to automate it?

How about a cronjob that runs darcs send <upstream-repo> --to=<some-list> ? Ganesh =============================================================================== Please access the attached hyperlink for an important electronic communications disclaimer: http://www.credit-suisse.com/legal/en/disclaimer_email_ib.html ===============================================================================

Simon Marlow wrote:

On 27/08/2009 11:18, Sittampalam, Ganesh wrote:

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Simon Marlow wrote:

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I suggest if we stick with the independent repo approach that we have some automation to check that changes are indeed getting pushed upstream.

Agreed. Can you think of an easy way to automate it?

How about a cronjob that runs

darcs send<upstream-repo> --to=<some-list>

?

But the requirement we want is that patches are only pushed upstream, and never pushed to the branch first.

I might be getting confused about something, but I'd expect this command to send an email with any changes in the branch repo that aren't in upstream. In other words if you have some patches in the branch that aren't upstream, you'll find out and can remedy the situation. Ganesh =============================================================================== Please access the attached hyperlink for an important electronic communications disclaimer: http://www.credit-suisse.com/legal/en/disclaimer_email_ib.html ===============================================================================

Simon Marlow wrote:

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Simon Marlow wrote:

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I suggest if we stick with the independent repo approach that we have some automation to check that changes are indeed getting pushed upstream.

[snip unhelpful suggestion from me]

Yes, it tells you that you've screwed up, rather than telling you that you're about to screw up, which would be much more convenient. After you've screwed up it might be too late to fix it, due to conflicts with upstream.

Can you arrange that the only way that patches can get into the branch is via darcs pull --intersection <upstream repo> ? Ganesh =============================================================================== Please access the attached hyperlink for an important electronic communications disclaimer: http://www.credit-suisse.com/legal/en/disclaimer_email_ib.html ===============================================================================

On 28/08/2009 10:05, Simon Marlow wrote:

On 27/08/2009 11:37, Sittampalam, Ganesh wrote:

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Simon Marlow wrote:

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Simon Marlow wrote: >> >> I suggest if we stick with the independent repo approach that we >> have some automation to check that changes are indeed getting >> pushed upstream. [snip unhelpful suggestion from me]

Yes, it tells you that you've screwed up, rather than telling you that you're about to screw up, which would be much more convenient. After you've screwed up it might be too late to fix it, due to conflicts with upstream.

Can you arrange that the only way that patches can get into the branch is via darcs pull --intersection<upstream repo> ?

That's an interesting idea, I'd forgotten about --intersection.

I have a script that works as a prehook (below). Unfortunately it doesn't work on darcs.haskell.org, I think because we only have darcs 1.0.9 there, and it is ignoring my prehook. Can anyone think of a good reason not to upgrade darcs to 2.3.0 on darcs.haskell.org? I can think of 3 reasons to do so: - this script, for preventing accidental divergence from upstream - faster pushes, due to transfer-mode - hide those annoying "Ignore-this: xxxxx" messages Cheers, Simon #!/bin/sh -e # checkupstream.sh # Only allow applying of patches that are also in this upstream repository: UPSTREAM=$1 # echo DARCS_PATCHES_XML = $DARCS_PATCHES_XML # Take $DARCS_PATCHES_XML and turn it into a list of patch hashes # suitable for looping over. hashes=`echo $DARCS_PATCHES_XML | sed 's|</patch>|</patch>\n|g' | sed -n '/hash/p' | sed "s|^.*hash='\([^']*\)'.*$|\1|"` # echo hashes: $hashes # For each patch, try pulling the patch from the upstream repo. If # the patch is not upstream, then fail. for p in $hashes; do if darcs pull --match="hash $p" $UPSTREAM --xml --dry-run | grep "$p"

/dev/null; then echo "Patch $p is upstream; ok" else echo "Patch $p is not upstream!" exit 1 fi done

exit 0

Duncan Coutts wrote:

On Fri, 2009-08-28 at 11:42 +0100, Simon Marlow wrote:

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Can anyone think of a good reason not to upgrade darcs to 2.3.0 on darcs.haskell.org? I can think of 3 reasons to do so:

- this script, for preventing accidental divergence from upstream - faster pushes, due to transfer-mode - hide those annoying "Ignore-this: xxxxx" messages

By the way, people who regularly work with the ghc repos (at least on Linux) and who are thinking of upgrading to darcs-2.3.0 should heed this advice:

Use "darcs get" to get your repos again. Not remotely, just locally. This switches them from darcs1 traditional format to darcs1 hashed format.

If you do this, then "darcs whatsnew" gets ~4 times quicker. If you do not do this, then "darcs whatsnew" gets ~100 times slower.

All times measured on Linux, local ext3 filesystem, ghc testsuite repo. All times are the second of two runs to allow for OS caching. The results may well be quite different on a different file systems, like Windows NTFS.

yes - on Windows things got slower with 2.3.0, even with hashed repositories: http://bugs.darcs.net/issue1585 Another thing to watch out for is that hashed repositories will automatically cache patches and pristine files in ~/.darcs/cache by default. If you home directory is NFS-mounted, this can be a bad idea. Even if you're not using NFS, the fact that pristine files are shared between all repositories means that darcs sometimes is a lot slower than it needs to be, because the timestamps on the pristine files are out of sync with the local repository (you'll see long "Reading pristine..." messages from darcs). I raised this on the darcs-users list before the 2.3.0 release, but as far as I know it isn't planned to be fixed until 2.4. Cheers, Simon

On 27/08/2009 00:55, Don Stewart wrote:

marlowsd:

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Simon and I have been chatting about how we accommodate libraries in the GHC repository. After previous discussion on this list, GHC has been gradually migrating towards having snapshots of libraries kept as tarballs in the repo (currently only "time" falls into this category), but I don't think we really evaluated the alternatives properly. Here's an attempt to do that, and to my mind the outcome is different: we really want to stick to having all libraries as separate repositories.

Background: * Scope: libraries that are needed to build GHC itself (aka "boot libraries")

* Boot libraries are of several kinds: - INDEPENDENT: Independently maintained (e.g. time, haskeline) - COUPLED: Tightly coupled to GHC, but used by others (base) - SPECIFIC: Totally specific to GHC (e.g. template-haskell, DPH)

* Most boot libraries are INDEPENDENT. INDEPENDENT libraries have a master repository somewhere separate from the GHC repositories.

* We need a branch of INDEPENDENT libraries, so that GHC builds don't break when the upstream package is modified.

* Sometimes we want to make local modifications to INDEPENDENT libraries: - when GHC adds a new warning, we need to fix instances of the warning in the library to keep the GHC build warning-free. - to check that the changes work, before pushing upstream

Choices for how we deal with libraries in the GHC repository: (+) is a pro, (-) is a con.

(1) Check out the library from a separate repo, using the darcs-all script. The repo may either be a GHC-specific branch [INDEPENDENT], or the master copy of the package [SPECIFIC/COUPLED].

(+) we can treat every library this way, which gives a consistent story. Consistency is good for developers. (+) [INDEPENDENT] makes it easy to push changes upstream and sync with the upstream repo (unless upstream is using a different VCS).

(-) [INDEPENDENT] we have to be careful not to let our branches get too far out of sync with upstream, and we must sync before releasing GHC.

(2) Put a snapshot tarball of the library in libraries/tarballs, but allow you to checkout the darcs repo instead.

(-) [SPECIFIC/COUPLED] this approach doesn't really make sense, because we expect to be modifying the library often. (-) updating the snapshot is awkward (-) workflow for making a change to the library is awkward: - checkout the darcs repo - make the change, validate it - push the change upstream (bump version?) - make a new snapshot tarball - commit the new snapshot to the GHC repo. (-) having tarballs in the repository is ugly (-) we have no revision history of the library

(3) The GHC repo *itself* contains every library unpacked in the tree. You are allowed to check out the darcs repo instead.

(+) atomic commits to both the library and GHC. (+) doing this consistently would allow us to remove darcs-all, giving a nice easy development workflow

(-) [INDEPENDENT/COUPLED] still need a separate darcs repo. (-) [INDEPENDENT/COUPLED] pushing changes upstream is hard (-) [INDEPENDENT/COUPLED] manual syncing with upstream (-) [COUPLED] (particularly base) syncing with upstream would be painful.

(3) works best for SPECIFIC libraries, whereas (1) works best for INDEPENDENT/COUPLED libraries. If we want to treat all libraries the same, then the only real option is (1).

Experience with Cabal and bytestring has shown that (1) can work for INDPENDENT libraries, but only if we're careful not to get too out-of-sync (as we did with bytestring). In the case of Cabal, we never have local changes in our branch that aren't in Cabal HEAD, and that works well.

Comments/thoughts?

As author of bytestring, I'd prefer it if GHC used a released version direct from Hackage. I.e. GHC could snapshot a Hackage release, and get out of the business of cloning repos. Same for other INDPENDENTs.

Are you saying you don't want us to have a GHC branch? Even if the branch just pulls from upstream and never has local changes? We can still use released versions only, the main point about having separate repos is that we have a consistent picture of libraries from GHC's side. For bytestring I imagine we can get away without making changes between releases, or at least ensuring our changes are sent upstream and we wait for a release before pulling. For other libraries, such as Cabal, this would be too onerous I think (Cabal is really COUPLED at the moment, much as we'd like it to be INDEPENDENT). Cheers, Simon

On 27/08/2009 11:25, José Pedro Magalhães wrote:

Hello,

On Wed, Aug 26, 2009 at 18:15, Simon Marlow mailto:marlowsd@gmail.com> wrote:

* Boot libraries are of several kinds: - INDEPENDENT: Independently maintained (e.g. time, haskeline) - COUPLED: Tightly coupled to GHC, but used by others (base) - SPECIFIC: Totally specific to GHC (e.g. template-haskell, DPH)

Does syb fall under INDEPENDENT or COUPLED?

In any case, as the syb maintainer, I'd favor (1) too.

I'd say at this stage it's INDEPENDENT. Thanks for the feedback! Cheers, Simon

2009/9/11 Ian Lynagh :

On Fri, Aug 28, 2009 at 10:06:36AM +0100, Simon Marlow wrote:

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On 27/08/2009 11:25, José Pedro Magalhães wrote:

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Hello,

On Wed, Aug 26, 2009 at 18:15, Simon Marlow mailto:marlowsd@gmail.com> wrote:

      * Boot libraries are of several kinds:        - INDEPENDENT: Independently maintained (e.g. time, haskeline)        - COUPLED: Tightly coupled to GHC, but used by others (base)        - SPECIFIC: Totally specific to GHC (e.g. template-haskell, DPH)

Does syb fall under INDEPENDENT or COUPLED?

In any case, as the syb maintainer, I'd favor (1) too.

I'd say at this stage it's INDEPENDENT.

I think that once we move rebase3-compat (in the next few days, in the HEAD), the only thing that needs syb is extcore. Is that sufficient that it is worth keeping it as a core lib?

I've meant for a long time to split off the ext-core library and put it on Hackage, since it isn't required to build GHC. I'll be doing that in the immediate future, so then, ext-core won't be a reason to keep syb coupled. Cheers, Tim -- Tim Chevalier * http://cs.pdx.edu/~tjc/ * Often in error, never in doubt "an intelligent person fights for lost causes,realizing that others are merely effects" -- E.E. Cummings