Re: [Xenomai] Q on xenomai2/3 userland coexistence

[Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>]

On Sat, Jun 27, 2015 at 02:43:39PM +0200, Gilles Chanteperdrix wrote:
> On Sat, Jun 27, 2015 at 02:22:09PM +0200, Michael Haberler wrote:
> > ATM we're sorting through the machinekit xenomai3 transition on
> > debian
> > 
> > I assume that users will continue to run xenomai2 kernels for a
> > long time, so we work towards separate (but hopefully
> > coexisting-in-peace) packages for Xenomai2 and Xenomai3 (startup
> > is driven by kernel autodetection, so booting a different kernel
> > chooses the right runtime)
> > 
> > The libxenomai-dev and libxenomai1 in debian are all xenomai2 atm,
> > but I assume Xenomai3 equivalents will appear eventually
> 
> Xenomai 3 has a debian directory allowing to build it as a Debian
> package. So, in fact, they are already here.
> 
> 
> > 
> > I hope these will be able to co-reside on the same host?
> > 
> > Ideally suggesting the Xenomai3 packages would be separate, be named differently, and not supersede any installed Xenomai2 packages?
> > 
> > 
> > (or am I blundering and I can run applications linked against the Xenomai3 libraries on a Xenomai2 kernel? my tests so far indicate - not)
> > 
> 
> I was afraid someone was going to ask for that. Experience has
> proved that allowing to install silently several versions of Xenomai
> is a recipe for trouble. So, relying on Debian allowing to install
> only one version of the package was a nice feature.
> 
> So, if we agree that having the two versions installed is not
> something for the common user, I would suggest people who want to do
> that know what they are doing and can install one version as a
> Debian package, and the other manually.
> 
> On the other hand, if we think having the two versions installed
> will be a very common use case, I do not think there is any conflict
> with library names, only with tool names, and since we provide the
> the "xeno" wrapper to fetch the tools from another place than
> /usr/bin, I guess the only conflict would be on the "xeno" wrapper
> itself. So, maybe we could call it xeno3 in Xenomai3 Debian package
> to avoid any issue? Or use the Debian "alternatives" mechanism
> (though this mechanism is probably unknown from the typical ubuntu
> user)? 

Other obvious conflicts are xeno-config, xeno-test. Of course, they
could be hidden behind the xeno wrapper as well. as xeno config and
xeno test.

-- 
					    Gilles.
https://click-hack.org