On Wed, 3 May 2017 22:47:18 +0100 James Le Cuirot <ch...@gentoo.org> wrote:
> On Wed, 3 May 2017 17:56:43 +0200 > Alexis Ballier <aball...@gentoo.org> wrote: > > > On Wed, 3 May 2017 12:05:48 +0200 > > "Paweł Hajdan, Jr." <phajdan...@gentoo.org> wrote: > > > > > I encountered <https://bugs.gentoo.org/show_bug.cgi?id=617276> > > > while working on some cross-compiling project. > > > > > > Admittedly, it may not be that easy to handle host package > > > dependencies fully automatically. > > > > > > I'm wondering - is it documented what portage guarantees, and > > > what I'm expected to just manually handle to provide host build > > > dependencies? > > > > > > Any other advice about properly using crossdev would also be > > > appreciated. I'd be happy to test and help improve things. > > > > > > From man emerge: > > > > > > --root-deps[=rdeps] > > If no argument is given then build-time dependencies > > of packages for ROOT are installed to ROOT instead of /. If the > > rdeps argument is given then discard all build-time > > dependencies of packages for ROOT. This option is only meaningful > > when used together with ROOT and it should not be enabled under > > normal circumstances! > > > > Does not affect EAPIs that support HDEPEND. > > Experimental EAPI 5-hdepend provides HDEPEND as a new means to > > adjust installation into "/" and ROOT. If ebuilds using EAPIs > > which do not support HDEPEND are built in the same > > emerge run as those using EAPIs which do support > > HDEPEND, this option affects only the former. > > > > > > crossdev wrappers set --root-deps=rdeps (read cross-emerge, this > > can be overriden), but be careful: If you only care about getting > > all the deps and maybe more then removing --root-deps might help > > you. However, when cross compiling you will likely run into broken > > deps since / and ROOT will not use the same keyword visibility. > > I was going to point to crossdev's use of --root-deps=rdeps too. I did > wonder why on earth this was even added. I overrode it for quite a > while and didn't have any issue. History showed that it was added by > solar without much of an explanation. He's no longer around to ask. It > wasn't until I tried to build a brand new ppc64le system recently that > I finally found a reason for it, though I'm not sure it was the > original reason. The multilib ABI USE flags start conflicting horribly > in cross situations and this option seems to be the only way around it > at present. there's that and e.g. you might want to enable USE=mmal for cross compiling to a raspberry pi; raspberrypi-userland will be in DEPEND but you wont be able to merge it into / > I doubt keyword visibility is an issue. Portage uses a different > configuration between / and ROOT when cross-compiling. I don't think > it tries to force the same package versions beyond what is specified > in the ebuild. For pure build-time dependencies, the package will > only be installed to / anyway (i.e. you don't need cmake in ROOT) so > there is nothing to enforce here. The issue is that we can't distinguish between target build time dependencies (libraries, headers, etc.) and host build time dependencies (cmake, autotools, etc.). While --root-deps=rdeps avoids most of the problems at the cost of missing host deps, it still fails horribly for target build time only deps (e.g. pure headers libraries).
