-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 On 12/08/15 01:50 PM, Ciaran McCreesh wrote: > On Wed, 12 Aug 2015 19:43:55 +0200 Ulrich Mueller > <u...@gentoo.org> wrote: >>>>>>> On Wed, 12 Aug 2015, Ulrich Mueller wrote: >>> Hm, how about adding a new PM command like "required_use foo >>> -bar"? It would be used exclusively in pkg_pretend, and tell >>> the PM to suggest the necessary package.use changes to the >>> user (or even update them automatically with the appropriate >>> --autounmask-* option). >> >> To clarify, I'm thinking about something like this: >> >> pkg_pretend() { if use qt4; then required_use -qt5 else >> required_use qt5 fi } >> >> The advantage would be that any number of elog messages could >> be added which would further explain things to the user. > > And how would the PM understand that -qt5 is conditional upon > qt4? Such knowledge is required if it's supposed to auto-resolve > stuff... >
I don't think required_use could auto-resolve here, without some other rather large changes to PMs -- for instance, the spec pkg_pretend likely needs to be assured to be taken into account before dependency resolution of that package somehow. Also, the required_use function needs to be permitted to modify effective-use and/or do whatever else it does, meaning that for what I believe is the first time we will have function calls in ebuilds modifying the precursors to dependency resolution dynamically rather than it being deterministic based on state and pre-defined static logic. (i hope that makes sense, unsure if i'm using anything even close to the correct terminology) -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iF4EAREIAAYFAlXLjWcACgkQAJxUfCtlWe2eDwEAzIcJWKlyFVbKzRCWIYEzP+JX DxdOOgnWd9IVfVdwAqQBAOQaJuXjPPpahfyq0qGQDjX6YKhGY2M2b/D/LjIV81HW =oko+ -----END PGP SIGNATURE-----