Rebuilding ghc changes interface hashes?

[Simon Marlow]

On 05/04/2011 23:14, Matthias Kilian wrote:
> On Tue, Apr 05, 2011 at 08:51:52PM +0100, Simon Marlow wrote:
>>> On Tue, Apr 05, 2011 at 09:59:23PM +0530, Joachim Breitner wrote:
>>>> Also, the initial upload was built using ghc-6.12.1, while the upload
>>>> now is build with ghc-7.0.2. Given that it is a two-stage compiler, I
>>>> assume that the output should be identical, but it seems not to be the
>>>> case.
>>>
>>> Changing the bootstrapping compiler changes the ABIs. The same can
>>> happen if you interrupt and restart the build.
>>
>> In general changes can creep in randomly, there's no direct link between
>> changing the bootstrap compiler and getting different compilation
>> results (as far as I know), but there are some small elements of
>> randomness.
>
> Oh, I confused those two problems again :-( But memories come back,
> and IIRC the problem with the bootstrapping compiler is caused by
> the "Booter version" (as printed by ghc --info) passed up to the
> stage2 compiler. Wasn't the plan (about a year ago) to remove this?

I don't think that is actually causing any problems.  It just means that 
stage2 claims to have been bootstrapped by whatever you used to build 
stage1.  Maybe that was intentional (Ian?).

Cheers,
	Simon


> If time permits, I'll send a patch in a few days, but I first have
> to follow the switch to git, and I also want to update our (OpenBSDs)
> ports to ghc-7.0.3 and hp-2011.2.
>
> Ciao,
> 	Kili