Changing port group default options

[Lawrence Velázquez]

On Mar 31, 2015, at 11:12 AM, Rainer Müller <raimue at macports.org> wrote:

> In my opinion, changes to the default behavior of port group options
> should be introduced with an increment of the port group version.
> 
> In this case, it would have worked like this:
> 
> 1. Add a new port group cmake-1.1.tcl with
>   'default cmake.out_of_source yes'
> 2. Update Portfiles to use 'PortGroup cmake 1.1', test build, and add
>   'cmake.out_of_source no' if required
> 
> This way, we would not have to touch all Portfiles a second time to
> remove the default option.

I suggested exactly this approach in #33259*, and I agree that it's the
better one. (Although I guess that didn't stop me from committing the
change.)

To me, the primary benefit of this approach is that it would prevent
confusing portgroup action-at-a-distance. It is not a good thing when
a portfile's behavior changes (apparently out of nowhere) due to
a change in a portgroup. Requiring a version bump would force this sort
of change to be handled explicitly and deliberately.

* https://trac.macports.org/ticket/33259#comment:44

vq