Gentoo Archives: gentoo-devhelp

From: Justin <justin@×××××××××.net>
To: gentoo-devhelp@l.g.o
Subject: Re: [gentoo-devhelp] Re: Writing ebuilds that replace others but with different name
Date: Fri, 25 Sep 2009 13:35:18
In Reply to: [gentoo-devhelp] Re: Writing ebuilds that replace others but with different name by Nikos Chantziaras
Nikos Chantziaras schrieb:
> On 09/24/2009 11:38 PM, Justin wrote: >> Nikos Chantziaras wrote: >>> I seem to have some fundamental "flaw" in portage. It seems I am not >>> able to write an ebuild that will in effect be able to replace another >>> one but with a different name. >>> >>> With RPMs, no matter how the RPM is named, it has "provides" data in it. >>> Is there some similar mechanism in portage? It seems to me that if >>> the >>> name of an ebuild is changed, then *all* ebuilds depending on it will >>> have to change too. That looks like a PITA to me if it's true. >>> >>> For example, if I have an overlay that provides alternative/altered >>> packages of already existing ones in the portage tree, they will "clash" >>> with portage. Let's assume that my overlay provides an ebuild called >>> "foo-alt" which is a variation of a package in portage called "foo", but >>> is totally compatible with it. What I'm looking for is being able to >>> emerge "foo-alt", but have the ebuild state clearly that it provides the >>> "foo" dependency, so ebuilds depending on "foo" will be satisfied if >>> "foo-alt" is installed but "foo" isn't. >>> >>> Possible? >>> >>> >> Thats's what virtuals are good for. As an example see virtual/jre. >> But in principle you are right. renaming a package is a headache and >> should really be avoided. > > I'm not sure how I can use virtuals to provide an alternative but > completely compatible package. I'll give a straight example: > > In my overlay, there's "x11-libs/qt-opengl-alt". It is a variation of > qt-opengl, providing and *replacing* all files in it. However, if I > unmerge qt-opengl and install qt-opengl-alt instead, even though the > installed packages depending on qt-opengl work perfectly fine with it > (it's fully compatible), an "emerge -uDN world" will try to pull > qt-opengl back in because it thinks it's missing (and this will of > course result in a file collision since qt-opengl-alt is also installed, > providing the same files). > > Changing the category also doesn't help ("x11-libs-alt/qt-opengl" for > example). > > So virtuals don't seem to have anything to do with with my problem. > What's missing is something like RPM's "provides" (so the qt-opengl-alt > ebuild would be able to say "I provide the qt-opengl package.) From > your answer, I take it that portage doesn't offer anything like this and > the ebuild's name is hardcoded to be the package it provides :P > >
Thats right, the only thing what you can do, is naming your ebuild x11-libs/qt-opengl as well and give it higher version number as the one in the tree.


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Subject Author
Re: [gentoo-devhelp] Re: Writing ebuilds that replace others but with different name "Sebastián Magrí" <sebasmagri@×××××.com>