Shake fails test with GHC 7.10 RC3

[Simon Peyton Jones]

OK

| -----Original Message-----
| From: mad.one at gmail.com [mailto:mad.one at gmail.com] On Behalf Of Austin
| Seipp
| Sent: 21 March 2015 20:45
| To: Neil Mitchell
| Cc: Herbert Valerio Riedel; Simon Peyton Jones; Austin Seipp; ghc-
| devs at haskell.org; ShanaTsunTsunLove
| Subject: Re: Shake fails test with GHC 7.10 RC3
| 
| Yes, this was what I was afraid of; an introduced regression in the RC
| 2-to-3 period, which IMO makes the bug a bit more serious. Also, this
| bug in particular looks like it manifests in a fairly nasty way, and
| having it catch people for the final release seems a bit worrisome.
| 
| I also just remembered that the Haddock documentation for 7.10.1 is
| still broken; I've been tracking the bug today, but I need to sync up
| with the Haddock maintainers to discuss more. I really think this one
| needs to be fixed.
| 
| So I also suggest we postpone for a few days to fix these two things,
| if possible.
| 
| On Sat, Mar 21, 2015 at 6:55 AM, Neil Mitchell <ndmitchell at gmail.com>
| wrote:
| > Interesting result. I've just attached a much smaller test case to the
| > ticket - it would be good to see if that fails or passes with RC2, or
| > breaks at the same point.
| >
| > The fact that there does seem to be a regression between RC2 and RC3
| > (either a regression itself, or making a previous bug easier to hit)
| > makes me think that a release might not be such a great idea.
| >
| > Thanks, Neil
| >
| >
| > On Sat, Mar 21, 2015 at 11:35 AM, Herbert Valerio Riedel
| > <hvriedel at gmail.com> wrote:
| >> On 2015-03-21 at 08:21:20 +0100, Herbert Valerio Riedel wrote:
| >>> On 2015-03-21 at 07:56:32 +0100, Neil Mitchell wrote:
| >>>
| >>> [...]
| >>>
| >>>> 3) I tested with GHC RC1 and GHC RC2, both of which were fine. The
| fact no
| >>>> one else hit this with RC2 might just be because its a very recent
| >>>> regression.
| >>>
| >>> We -- and by that I don't mean myself... :) -- could git-bisect
| between
| >>> RC2 and RC3 here (semi-)automatically (i.e. maybe unattended if it's
| >>> scriptable) if your test-case (even if it's not minimal) reliably
| >>> triggers the bug...
| >>
| >> I scripted up a test and git-bisected between RC2 and RC3, and the
| >> following commit is the one where `shake-test oracle test` starts
| >> failing
| >>
| >>
| http://git.haskell.org/ghc.git/commitdiff/6f46fe15af397d448438c6b93babcdd
| 68dd78df8
| >>
| >> ...which sadly is a rather large patch :-/
| >
| 
| 
| 
| --
| Regards,
| 
| Austin Seipp, Haskell Consultant
| Well-Typed LLP, http://www.well-typed.com/