Tentative high-level plans for 7.10.1

Tue Oct 7 23:56:13 UTC 2014

Ok, if the ghc devs decide to do a 7.8.4 release, I will explicitly commit
to helping backport patches.

However, I don't know how to do so.  Therefore, I'm going to ask Austin (as
he's probably the most knowledgeable) to update the 7.8.4 wiki page with
the process people should use to contribute backports.  I'm guessing it's
probably something like this:

checkout the 7.8.4 release branch (which branch is it? ghc-7.8?)
git cherry-pick the desired commit(s)
? (make a phab request for ghc-hq to review?)
update Trac with what you've done

(or if this is already documented somewhere, please point me to it).

Unfortunately this doesn't have any way of showing that I'm working on a
specific backport/merge, so there's potential for duplicate work, which
isn't great.  I also agree with Nicolas that it's likely possible to make
better use of git to help with this sort of work, but that's a decision for
ghc hq so I won't say any more on that.

Cheers,
John

On Tue, Oct 7, 2014 at 4:12 PM, Simon Peyton Jones <simonpj at microsoft.com>
wrote:

> Thanks for this debate.  (And thank you Austin for provoking it by
> articulating a medium term plan.)
>
> Our intent has always been that that the latest version on each branch is
> solid.  There have been one or two occasions when we have knowingly
> abandoned a dodgy release branch entirely, but not many.
>
> So I think the major trick we are missing is this:
>
>    We don't know what the show-stopping bugs on a branch are
>
> For example, here are three responses to Austin's message:
>
> |  The only potential issue here is that not a single 7.8 release will be
> |  able to bootstrap LLVM-only targets due to #9439. I'm not sure how
>
> | 8960 looks rather serious and potentially makes all of 7.8 a no-go
> | for some users.
>
> |  We continue to use 7.2, at least partly because all newer versions of
> |  ghc have had significant bugs that affect us
>
> That's not good. Austin's message said about 7.8.4 "No particular pressure
> on any outstanding bugs to release immediately". There are several dozen
> tickets queued up on 7.8.4 (see here
> https://ghc.haskell.org/trac/ghc/wiki/Status/GHC-7.8.4), but 95% of them
> are "nice to have".
>
> So clearly the message is not getting through.
>
>
> My conclusion
>
>  * I think we (collectively!) should make a serious attempt to fix
> show-stopping
>    bugs on a major release branch.  (I agree that upgrading to the next
> major
>    release often simply brings in a new wave of bugs because of GHC's
>    rapid development culture.)
>
>  * We can only possibly do this if
>    a) we can distinguish "show-stopping" from "nice to have"
>    b) we get some help (thank you John Lato for implicitly offering)
>
> I would define a "show-stopping" bug as one that simply prevents you from
> using the release altogether, or imposes a very large cost at the user end.
>
> For mechanism I suggest this.  On the 7.8.4 status page (or in general, on
> the release branch page you want to influence), create a section "Show
> stoppers" with a list of the show-stopping bugs, including some
> English-language text saying who cares so much and why.  (Yes I know that
> it might be there in the ticket, but the impact is much greater if there is
> an explicit list of two or three personal statements up front.)
>
> Concerning 7.8.4 itself, I think we could review the decision to abandon
> it, in the light of new information.  We might, for example, fix
> show-stoppers, include fixes that are easy to apply, and not-include other
> fixes that are harder.
>
> Opinions?  I'm not making a ruling here!
>
> Simon
>
> |  -----Original Message-----
> |  From: ghc-devs [mailto:ghc-devs-bounces at haskell.org] On Behalf Of Ben
> |  Gamari
> |  Sent: 04 October 2014 04:52
> |  To: Austin Seipp; ghc-devs at haskell.org
> |  Cc: Simon Marlow
> |  Subject: Re: Tentative high-level plans for 7.10.1
> |
> |  Austin Seipp <austin at well-typed.com> writes:
> |
> |  snip.
> |
> |  >
> |  > We do not believe we will ship a 7.8.4 at all, contrary to what you
> |  > may have seen on Trac - we never decided definitively, but there is
> |  > likely not enough time. Over the next few days, I will remove the
> |  > defunct 7.8.4 milestone, and re-triage the assigned tickets.
> |  >
> |  The only potential issue here is that not a single 7.8 release will be
> |  able to bootstrap LLVM-only targets due to #9439. I'm not sure how
> |  much of an issue this will be in practice but there should probably be
> |  some discussion with packagers to ensure that 7.8 is skipped on
> |  affected platforms lest users be stuck with no functional stage 0
> |  compiler.
> |
> |  Cheers,
> |
> |  - Ben
>
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