This change prevents guix system from erroring out with an ugly backtrace
when it's passed an invalid value to the “--system” or “--target”
option. It also adds the “--list-systems” and “--list-targets” options.
The manual section about guix system doesn't mention the “--target” option,
so add it there.
* guix/scripts/system (show-help): Call show-cross-build-options-help and
show-native-build-options-help.
(%options): Remove own implementation of “system” and “target” options and
use the ones in %standard-cross-build-options and
%standard-native-build-options.
* doc/guix.texi (Invoking guix system): Document “--target” option.
Signed-off-by: Mathieu Othacehe <othacehe@gnu.org>
65ce5fe2fb