Subject: Re: bug#26201: No notification of cache misses when downloading substitutes

From: Tobias Geerinckx-Rice <[email-masked]>
Date: Tue, 21 Mar 2017 07:21:54 +0100

Mornin',

On 21/03/17 05:48, [email-masked] wrote:
> I'm not suggesting having Guix tell me why my network is slow,

I never mentioned your network. Your proxied connection to a substitute
server, yes. And, well, this very bug report is for Guix to tell you why
that's slow...

> only if the download might be slow because it's having to pull from 
> hydra.gnu.org.

(Side note: ‘it’ here is mirror.hydra.gnu.org, never a well-configured
Guix client.)

So to implement this, the client would need to display a ‘warning‘
message or flag sent by the substitute server, to notify the user that
their download might be slower... sometimes... by an unknown amount...
possibly?

But see, that wouldn't be true at all on my system (and surely others),
despite being set up nearly identically to Hydra. On the other hand, my
home download speed fluctuates wildly, even between simultaneous
connections to the same server. Whether or not a file is cached makes no
difference. To be told would be noise at best, misleading at worst.

I'd be against this only for those reasons, but I promise I'm not.

It's just all a bit vague, 's all, and my personal opinion is that once
the vagueness is resolved, not much will remain. But who knows.

> AFAIK, Guix devs are working on a replacement for the current build 
> system, so the sane option wouldn't be extending the current hydra 
> system to handle a new API call, but to try and work this type of 
> feature into the next system.

My point is that it wouldn't be sane, and would be an ugly hack in
either system. Cuirass isn't really different from Hydra is this regard.

Me shut up now :-) I'm more interested in what others have to say.

Kind regards,

T G-R