Options NG questions

[Matthias Andree]

Greetings,

while porting dnsmasq to optionsNG, I came across a couple of questions
that do not seem to be addressed in the documentation.

1 - dependencies between options

specifics: dns/dnsmasq offers IDN and NLS. Due to idiosyncrasies of the
port, NLS also entails IDN. Meaning that:

If NLS is enabled,  the IDN option should either *not* be offered, or as
"always on".

If NLS is disabled, the IDN option *should be offered* as a binary option.

How do I express that in Options NG?


2 - OPTIONS_EXCLUDE

OPTIONS_EXCLUDE does not seem to work for me in a way that I've
understood it.

Situation: misc/e2fsprogs-libuuid (a slave port to sysutils/e2fsprogs)
requires WITHOUT_NLS=true to build properly, OPTIONS_EXCLUDE=NLS does
not work (meaning that the master port gets NLS in PORT_OPTIONS breaking
the slave build), WITHOUT_NLS=true continues to work.


3 - Command line overrides

Traditionally, command line overrides like "make WITHOUT_IPV6=yes" took
precedence, or port test -- WITHOUT_IPV6.

How do I tell dns/dnsmasq after conversion that I do not want IPV6?
"make OPTIONS_UNSET=IPV6" does not work, and "make OPTIONS_OVERRIDE=..."
requires a lot of fiddling to get the options right.

Best,
Matthias