The dlang repository offers a gcc ebuild that adds the patchset to build the gdc. It's behind a USE-Flag. Still it is exactly the same as sys-devel/gcc::gentoo besides the additional feature.
But I don't think the dlang repo should mask gcc::gentoo.

2018-03-23 12:18 GMT+02:00 Francesco Riosa <vivo75@gmail.com>:


Il 23/03/2018 10:48, Ulrich Mueller ha scritto:
>>>>>> On Thu, 22 Mar 2018, Geaaru  wrote:
>> for both portage and your fork I think that could be interesting add
>> an extension to PMS for define inside profiles or targets masking of
>> packages of a particular repslository. Currently PMS doesn't permit
>> this but have this feature could be help users to define our
>> profiles under overlays.
>> Something like this:
>> sys-devel/gcc::gentoo
> Conceptually that makes no sense. sys-devel/gcc is the name of an
> upstream package, so what does it even mean to mask it in one
> repository but not in another? If it's the same package, then it
> should behave in the same way, regardless of the repository its ebuild
> it hosted in (or the package being installed, in which case it is no
> longer in an ebuild repository).
>
> If it is a different package however, then it should have a different
> name.
Sorry to say it bluntly but this make no sense at all, even changing a
USE flag make the package behave wildly differently.
Once we agree that an upstream (complex enough) package may have
different incarnations two ebuilds from different maintainers may please
differently the user.
I'm not sure this choice belong to profiles but not because same
upstream correspond to same files on filesystem.

>
> Ulrich