Ludovic Courtès <ludo@gnu.org> writes:

> Hi,
>
> Ludovic Courtès <ludo@gnu.org> skribis:
>
>> Christopher Baines <mail@cbaines.net> skribis:
>>
>>> Following up on this, I've built Guile on core-updates with libgc@7
>>> rather than libgc@8 (which is what's used above), and I can't reproduce
>>> the issue. So, I'm getting more certain that this is a regression which
>>> the libgc upgrade has led to.
>>
>> Bah.  :-/
>>
>> We noticed similar issues with libgc@8 earlier but it seemed to be
>> fixed:
>>
>>   https://debbugs.gnu.org/cgi/bugreport.cgi?bug=36812
>>
>>> Would it be feasible to keep guile, or at least the guile Guix uses with
>>> libgc@7 for now?
>>
>> Yes, we can define a Guile variant in (gnu packages guile) and have
>> (guix self) refer to it.
>
> FWIW flatwhatson reported the dreaded libgc “mmap(PROT_NONE)” crash
> upstream and gathered more info:
>
>   https://github.com/ivmai/bdwgc/issues/353
>
> On #guile they also mentioned that libgc 8 defaults to
> ‘--enable-munmap=6’ whereas libgc 7 would default to ‘--disable-munmap’.
>
> Thus, in ‘core-updates’ commit a605ef3ce9dbd6b79dd9322f89d9facaf875b487,
> I changed libgc 8 so it’s built with ‘--disable-munmap’.  This relieves
> the need for ‘guile-3.0/libgc-7’.  (I checked with “make as-derivation”
> on x86_64-linux that those derivations that would previously fail with
> libgc 8 no longer do.)

Great, that sounds good :)