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.
> 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
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