Re: [gentoo-dev] RFC: multiple inheritance support for profiles

[Brian Harring]

On Sat, Aug 12, 2006 at 01:24:49PM -0700, Zac Medico wrote:
> Hi everyone,
>
> Currently, portage only allows single inheritance in profiles, but
> it's easy to enable multiple inheritance.  In order to do this, we
> only need to unconstrain the number of parents allowed in the parent
> file (only 1 is currently allowed).  When a parent file contains
> multiple parents, parents listed later if the file will have the
> ability to override those listed earlier in the file.
>
> Multiple inheritance seems like it would add useful flexibility to
> the profile structure.

Unfortunately, portages long time handling of N parents sucks.

> Should we remove the single inheritance
> constraint and allow multiple inheritance?

Said single inheritance protection was added 06/05/06 (rev 3544), 
stabled for x86 roughly 06/22/06.

Hasn't even yet made it to a release media- meaning folk installing 
from the most current release media still can get bit in the ass by 
switching to an N parent from the get go.

So... basic question is how this is actually going to protect users 
from stumbling into it?

There *are* a lot of folk who let things linger, and 2.1 (not 2.1.1 
holding said rev) held the major reason to upgrade, 2.1.1 being just 
bug fixups.  Point I'm trying to get across here is that there are 
still going to be a fair chunk of folk lacking the protection; combine 
that with the long standing capability to nag users to upgrade their 
profiles, and you've got the core reason this support isn't already in 
portage- if a user upgrades without the protection, they wind up with 
only half of the profile (best case).

Move forward with it, but even if support exists, it still must sit 
for long enough to avoid screwing over anyone but the biggest 
slackers- this would include ensuring that the appropriate portage dep 
is in both branches; do that, and you've minimized it as much as 
possible.

So... what's the plan in that regard?
~harring