Hi Mark,

> Note that we also lost 'icecat' on armhf-linux with the 52->60 upgrade,
> because our 'rust' packages have never worked on armhf-linux.

Wait, what?  I wasn't aware.  Let's track this as a bug - that's
definitely not supposed to happen.

mrustc works on armhf - I tested it on physical armhf hardware before merging.

So one of the other Rusts doesn't work?  I'll check out Hydra logs...

https://hydra.gnu.org/build/3215481/nixlog/1/raw indicates a timeout of
silence - we might want to increase it.  (this particular step takes many
many MANY minutes on x86_64, too).

Would that be the "(properties '((timeout . 3600)))))" thing?  Or is a
"timeout of silence" an extra setting?