Subject: Re: chat/gaim and options
To: None <segv@netctl.net>
From: Greg Troxel <gdt@ir.bbn.com>
List: tech-pkg
Date: 11/22/2005 19:37:22
segv@netctl.net writes:

> On Tue, 22 Nov 2005 20:28:04 +0100
> Roland Illig <rillig@NetBSD.org> wrote:
> 
> > segv@netctl.net wrote:
> >
> > Would adding this additional sentence have helped you?
> > 
> >      To disable an option, prefix it with a dash (-).
> 
> Yes, I think it would, because I had no idea you could disable them
> with a dash.

That helps, because the semantics of package options are confusing.  I
understand why they are like they are; I think the confusion is
intrinsic to the power.

The problem is that a reasonable person may expect that setting
PKG_OPTIONS.gaim to cause the set of selected options to be exactly
the value of the variable; that's "obviously" what the variable
means.  So perhaps

  The set of selected options is the default for the package, modified
  by PKG_DEFAULT_OPTIONS (with -option meaning to unset an option),
  then modified by PKG_OPTIONS.$pkgname.  Thus, to disable a default
  option foo, you must set either PKG_DEFAULT_OPTIONS=-foo or
  PKG_OPTIONS.$pkgname=-foo.

But this is too lengthy.

Section 5.4 of the Guide explains this correctly, but with even more
text.  Perhaps a pointer to section 5.4 of the guide would be better
than trying to explain something complicated too quickly.

-- 
        Greg Troxel <gdt@ir.bbn.com>