>>>>> On Fri, 20 May 2016, Michał Górny wrote:

> Sometime around a year ago, I started working on extending
> INSTALL_MASK to support well-defined locations. The work was never
> finished, and I just found my old specification for it. I've cleaned
> it up a bit, and extended it into a complete GLEP covering
> INSTALL_MASK [1].

> Please review the specification provided. The basic goal is to
> provide an ability to use INSTALL_MASK alike USE flags -- with path
> groups that are well-defined and described in the repository.

Sorry, I am late in the game. (Or maybe not, since the GLEP doesn't
yet have a number.)

The GLEP says that path groups always apply globally. So the
install-mask.conf file is not "alike layout.conf" (as the GLEP claims)
because its scope is not restricted to the repository where it is
stored. And in turn this can lead to name collisions ("Duplicate
groups [...] are considered an error").

Therefore I think that repository metadata is the wrong place for
storing the install-mask.conf file. It is configuration, specific to
Portage (but not to the repository), so /usr/share/portage/config/
would be a better location to store it. 

Ulrich

> [1]:https://wiki.gentoo.org/wiki/User:MGorny/GLEP:INSTALL_MASK