Re: [gentoo-dev] HDEPEND (host dependencies for cross-compilation) for EAPI 5?

[Richard Yao]

On 08/31/2012 04:03 PM, Zac Medico wrote:
> For those who may not know, chromium-os currently uses a
> hard-host-depends ebuild as a workaround for our lack of HDEPEND support
> [1]. We could easily add HDEPEND in EAPI 5 if we want, since we already
> have a Portage patch attached to bug #317337 [2]. Here is a summary of
> what that Portage patch will do:
>
> In EAPI 5 or later, DEPEND has been divided into two parts:
> DEPEND for build-time target dependencies, and HDEPEND for
> build-time host dependencies. This division is designed
> specifically to minimize difficulty in the process of
> adapting ebuilds that were written for earlier EAPIs,
> and therefore it also minimizes the adjustments that
> ebuild developers will have to make to the thought
> processes involved when writing ebuilds from scratch. In
> an environment that does not involve cross-compilation,
> HDEPEND behaves the same as DEPEND. When an ebuild is
> converted from EAPI 4 or earlier to EAPI 5 or later,
> in order to support cross-compilation environments, some
> dependencies may need to be migrated to HDEPEND.
>
> For ebuilds that have EAPI 5 or later, the emerge
> --root-deps option has no effect since it is made obsolete
> by division between DEPEND and HDEPEND. If EAPI 4 or
> earlier ebuilds are used in combination with EAPI 5 or
> later ebuilds, the --root-deps behavior will still be
> applied to the EAPI 4 or earlier ebuilds (there is no
> behavior change for ebuilds having older EAPIs).
>
> [1]
> http://www.chromium.org/chromium-os/how-tos-and-troubleshooting/portage-build-faq
> [2] https://bugs.gentoo.org/show_bug.cgi?id=317337

I like this. It has my support.