bug#26976: On Hydra, offload crashes while trying to build linux-libre source

[Ludovic Courtès]

(+ Cc: guix-sysadmin)

address@hidden (Ludovic Courtès) skribis:

> I’ve pushed a workaround that seems to work (‘guix copy’ commands that
> previously segfaulted on hydra.gnu.org no longer do):
>
>   
> https://git.savannah.gnu.org/cgit/guix.git/commit/?id=8e469b67f95cfe5b95405b503b8ee315fdf8ce66
>
> The idea is simply to explicitly close all the channel ports.  That way,
> when their finalizer gets called, it doesn’t invoke libssh code.
>
> (guix build offload) and (guix ssh) already explicitly close all the
> channel ports they open, so I found that the culprit is ‘node-eval’ in
> Guile-SSH.  The patch changes ‘node-eval’ to explicitly close the RREPL
> channel upon completion.  (BTW, performance-wise, it may be best to
> avoid opening a new channel every time ‘node-eval’ is called.)
>
> That may be good enough for Guix, but of course that’s a workaround and
> not a proper fix.
>
> I’ll do some more testing and then maybe try switching hydra.gnu.org to
> Guile 2.2 again.

After some more testing, I’ve upgraded hydra.gnu.org to
/gnu/store/4p56wc3lmr177ffw0zkjdwcmm3cb18wx-guix-0.13.0-2.de9d8f0 (from
/gnu/store/cxmj38x6rh0ykq3d5dlqbxr5h1zgiiaf-guile2.0-guix-0.13.0-1.a6d728b).
So far so good, but let’s keep an eye on the ongoing builds.  We can
always roll back if it turns out my optimism was misplaced.

Ludo’.