Re: Guix on aarch64

[Ludovic Courtès]

Hi Mark,

Mark H Weaver <address@hidden> skribis:

> The 'guix publish' TTL is a secondary issue, because, as you say, the
> NARs are only deleted if the corresponding store item has been GC'd.
> The more important question is: what is the policy for deleting GC roots
> on Berlin?

As I wrote, there’s no policy other than “make sure there’s at least N
GiB free.”

I think the ‘guix publish’ TTL is not a secondary issue if the question
is “what does it take for substitutes to remain available?”  GC roots
allow us to retain substitutes regardless of their popularity (so it’s
definitely useful for releases), while the TTL allow us to retain
popular substitutes.

I think I already wrote that I acknowledge the issues you raised and
that we should fix Cuirass to create GC roots for evaluations when we
ask it to.

Ricardo Wurmus <address@hidden> skribis:

> I think our use of Hydra is not sustainable.  It requires regular manual
> intervention by Mark, careful tuning of SQL queries, conscientious
> clean up of old substitutes, and we have not a single person familiar
> with the Perl code.
>
> We do have people working on Cuirass, though.  Let’s add important
> missing features to Cuirass instead of making efforts to keep Hydra on
> life support.

+1

To be clear, I want us to switch to berlin as the main official
substitute server in the coming weeks.  Emacs-build-farm and the web
interface are becoming pretty nice.  There _are_ missing features and
rough edges, but I’d like us to focus on addressing those.

The Cuirass web interface code is nice and pleasant to work with, so I
encourage everyone to take a look and add whatever they deem important!

  
https://git.savannah.gnu.org/cgit/guix/guix-cuirass.git/tree/src/cuirass/http.scm
  
https://git.savannah.gnu.org/cgit/guix/guix-cuirass.git/tree/src/cuirass/templates.scm

I also think it’s important to be able to react calmly and
constructively to issues like the one Benjamin reported.  It’s not a
minor issue, but if we want to be address it in good conditions, we have
to keep cool and focus on concrete incremental steps we can take to
address it, while also keeping in mind our longer-term goals.

Thanks,
Ludo’.