bug#24703: Re: bug#24703: Store references in 8-byte chunks in compiled code

[Mark H Weaver <mhw@netris.org>]

Török Edwin <edwin+ml-guix@etorok.net> writes:

> On 2016-10-16 22:04, Ludovic Courtès wrote:
>> Mark H Weaver <mhw@netris.org> skribis:
>> 
>>> When grafting, how will we achieve confidence that we've found the
>>> correct occurrence of the last character?  I think we will have to give
>>> up our recently added feature of being able to change the version number
>>> of grafts.
>> 
>> Wait, don’t jump to the conclusions.  :-)
>
> I've just encountered the same problem with fontconfig (after
> installing GuixSD, running guix pull and guix system reconfigure,
> --no-grafts was required).

Here's how to recover, for now:

  guix build --no-grafts -e '(@@ (gnu packages fontutils) fontconfig/fixed)'

> Would it be possible for the grafts to keep a symlink (somehow
> registered to be part of the grafted fontconfig so that guix gc
> doesn't remove it) instead of patching the binaries?
> /gnu/store/<old-hash>-fontconfig-2.11.94 -> /gnu/store/<grafted-hash>-fontconfig-2.11.94

This would effectively mutate the store, and we must never do this.

      Mark