This will make it an error if no suitable system gcc is found.

It can be overridden by the user by --without-system-gcc. Our gcc stands out from other SPKGs because building it often fails, for example because suitable binutils are lacking.

(from https://groups.google.com/g/sage-devel/c/cSsAsPuVnxg/m/fDBOSaYZBgAJ)

Currently, force leads to immediate exit, without printing the system package advice. We also change this. This is a useful improvement in its own right.

Discussion of other packages to which the same logic should be applied is beyond the scope of the present ticket.

CC: @dimpase @seblabbe @slel @kliem @orlitzky @vbraun

Component: build: configure

Author: Matthias Koeppe

Branch/Commit: 19efe21

Reviewer: Dima Pasechnik

Issue created by migration from https://trac.sagemath.org/ticket/32060