Hi Christophe,

On Wed, 22 Aug 2018 at 15:33, Christophe Demarey
<[email protected]> wrote:
>
> Hi Alistair,
>
> > Le 22 août 2018 à 12:02, Alistair Grant <[email protected]> a écrit :
> >
> > Hi Christophe,
> >
> > On Wed, 22 Aug 2018 at 09:36, Christophe Demarey
> > <[email protected]> wrote:
> >>
> >> ...
> >>
> >> As a workaround for now, we are thinking to ship the pharo.version file 
> >> along with the image to avoid to run images with compatible VMs that we 
> >> cannot ensure they work well with a given image.
> >
> > Part of the issue here is that Pharo 7 is still  in development.  My
> > understanding is that within the development cycle we assume that the
> > latest VM is being used (if I'm wrong, I'm sure someone will correct
> > me :-)).
> >
> > I don't use Pharo Launcher, so I'm not familiar with it, but it seems
> > to me that for the current development version (currently Pharo 7) the
> > launcher needs to ensure that it has the latest stable VM.
>
> You’re right but the problem is that Pharo Launcher has no way to know what 
> is the pharo version of an image before running it and evaluate a small 
> expression. To achieve that, Pharo Launcher uses a VM that is, at least, 
> compatible with the image format number. We do not have any guarantee that 
> the expression evaluation of the VM will work fine for all images. For now, 
> to detect the pharo version of Spur images, we use Pharo 61 VM. You can 
> assume it will work well for 6. images. What if we use the 70 VM to determine 
> pharo version of 6.* images? It will probably work better for Pharo 7 images 
> (assuming we use the latest 70 VM) but then, no guarantee it will work for 61 
> images.
>
> The core of the problem is that we should not be forced to run an image to 
> determine its pharo version. Nevertheless, I think it would be good to use 
> the latest available VM for a given image format to determine its pharo 
> version. It should work in most cases.

Thanks very much for the explanation, it makes sense now.

My understanding is that the Pharo 7 VM is backward compatible with
Pharo 6.1 (for now).  Esteban's process is to release a new stable
Pharo 7 VM, and then a month later upgrade the Pharo 6.1 VM as well.
Of course, that will be superseded by the availability of
pharo.version.

Thanks again,
Alistair

Reply via email to