Shake fails test with GHC 7.10 RC3

[Iavor Diatchki]

This is very odd---the example on the ticket does not use `Typeable` at all.

I looked through the diffs of the patch and I can't see anything obviously
wrong.

Also, the `Typeable` code only touches modules that are in the front-end,
and when I compile without optimizations, the example looks reasonable.

I wonder if the problem is related to some odd interaction between
simplification rules and representational equities?





On Sat, Mar 21, 2015 at 4:35 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/6f46fe15af397d448438c6b93babcdd68dd78df8
>
> ...which sadly is a rather large patch :-/
> _______________________________________________
> ghc-devs mailing list
> ghc-devs at haskell.org
> http://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-devs
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.haskell.org/pipermail/ghc-devs/attachments/20150321/369eaabd/attachment.html>