bug#43565: cuirass: Fibers scheduling blocked.

[Ludovic Courtès]

Hi,

Mathieu Othacehe <othacehe@gnu.org> skribis:

> Today between 04:04 and 10:36 no inputs were fetched. Fetching is
> supposed to happen every 5 minutes. This seem to be correlated to the
> duration of the garbage collection happening on berlin.
>
> 2020-09-22T04:04:23 fetching input 'core-updates' of spec 
> 'core-updates-core-updates'
> 2020-09-22T04:04:25 build succeeded: 
> '/gnu/store/c7m6jxdkyjs7m5ynavagjwgp172a3xzv-partition.img.drv'
> waiting for the big garbage collector lock...
> ...
> 2020-09-22T10:36:02 fetching input 'guix' of spec 'guix-master'
>
> A potential cause is described here:
> https://issues.guix.gnu.org/43552#1.

‘process-build-log’ in Cuirass uses ‘read-line/non-blocking’ to read a
line from the log port of ‘build-derivations&’.  If that really is
non-blocking (and I think it is), then we should be fine?

We should attach GDB to Cuirass next time to see what’s blocking.

Ludo’.