‘computed-origin-method’ for IceCat and ungoogled-chromium

[Ludovic Courtès]

Hello Mark & Marius!

Somehow I hadn’t noticed the clever trick with ‘computed-origin-method’
in IceCat and ungoogled-chromium, and it came to me as a shock today.
;-)

I stumbled upon it while traversing packages with ‘guix lint’ because
they violated the assumption that the ‘sha256’ field of <origin> is
always a bytevector.

I suspect this could be rewritten by using ‘computed-file’ instead of
<origin>.  This should be clearer, I think, notably because it would
avoid exposing a “non-conforming” <origin>.

WDYT?

Ludo’.