bug#29814: impossible to pass spaces in GUIX_BUILD_OPTIONS

[ludo@gnu.org (Ludovic Courtès)]

Mark H Weaver <mhw@netris.org> skribis:

> ludo@gnu.org (Ludovic Courtès) writes:

[...]

>> Yes, this is annoying.  I think --substitute-urls (plural) was
>> misguided.  Instead we should instead have --substitute-url (singular),
>> which could be repeated several times.  That would solve the troubles
>> with spaces.
>>
>> During a transition period we could keep accepting --substitute-urls.
>
> I require a way to clear the list of substitute urls, because last I
> checked --no-substitutes doesn't fully inhibit use of the substitute
> servers.  For example, I found that when grafting, substitute servers
> were queried even when --no-substitutes is passed to the daemon.  I
> guess that's to determine the set of references found in the build
> outputs, to optimize the grafting process.  However, a compromised
> substitute server (or a man-in-the-middle in possession of our signing
> key) could send me the wrong set of references, and thus cause my system
> to perform incomplete grafts, with some dependencies omitted from the
> list of rewrites.

AFAIK when ‘guix-daemon --no-substitutes’ is running what you describe
is impossible.  If the impossible happens, could you report a bug?

> My current method to avoid trusting the substitute servers is to pass
> both --no-substitutes and --substitute-urls "" to the daemon.  If we
> deprecate the use of --substitute-urls, how will I clear the list?

Normally, both for the daemon and for clients, --no-substitutes should
achieve what you want.  If not, we should really fix it.

Thanks,
Ludo’.