bug#50557: Unable to access remote logs

[Ludovic Courtès]

Hi Sarah,

Sarah Morgensen <iskarian@mgsn.dev> skribis:

> For whatever reason, it seems build logs are not available from
> ci.guix.gnu.org and bordeaux.guix.gnu.org.  "Invoking guix publish" says
> that they should be available at /log/store-name, but...
>
> $ guix build hello
> 0.1 MB will be downloaded:
>    /gnu/store/a462kby1q51ndvxdv3b6p0rsixxrgx1h-hello-2.10
> substituting /gnu/store/a462kby1q51ndvxdv3b6p0rsixxrgx1h-hello-2.10...
> downloading from 
> https://ci.guix.gnu.org/nar/lzip/a462kby1q51ndvxdv3b6p0rsixxrgx1h-hello-2.10 
> ...
>  hello-2.10  51KiB                                                        
> 249KiB/s 00:00 [##################] 100.0%
>
> /gnu/store/a462kby1q51ndvxdv3b6p0rsixxrgx1h-hello-2.10
>
> $ wget https://ci.guix.gnu.org/log/a462kby1q51ndvxdv3b6p0rsixxrgx1h-hello-2.10
> --2021-09-12 18:05:39--  
> https://ci.guix.gnu.org/log/a462kby1q51ndvxdv3b6p0rsixxrgx1h-hello-2.10
> Resolving ci.guix.gnu.org (ci.guix.gnu.org)... 141.80.181.40
> Connecting to ci.guix.gnu.org (ci.guix.gnu.org)|141.80.181.40|:443... 
> connected.
> HTTP request sent, awaiting response... 404 Not Found
> 2021-09-12 18:05:40 ERROR 404: Not Found.
>
> $ guix build hello --log-file
> guix build: error: no build log for 
> '/gnu/store/a462kby1q51ndvxdv3b6p0rsixxrgx1h-hello-2.10'

Yes, this is a side effect of the new Cuirass architecture, deployed a
few months ago: it used to be that packages were built via offloading,
and thus berlin (the front-end of ci.guix) would have build logs
available locally; now that Cuirass’s own remote build mechanism is
used, berlin no longer has build logs, hence this issue.

Mathieu, can you think of a way we could address this?  Maybe Cuirass
could handle those /log URLs since it already has build log URLs anyway?

Thanks,
Ludo’.