Package "mounting" proposal

[Simon Marlow]

Stefan Karrmann wrote:
> My 2 cents:
> 
> Sven Moritz Hallberg (Sun, Jul 16, 2006 at 01:24:43AM +0200):
> 
>>[...]
>>She must specify it somehow. Two possibilities come to mind:
>>
>>  1. Add a field to the package description of foo (v1.4, say) that says
>>     "I'm backwards-compatible with 1.3." When building, this relation
>>     would have to be inspected to see whether any currently installed
>>     version of foo satisfies the dependency specified by the mount.
>>  2. Declare a convention for version numbers to carry compatibility
>>     information, like the OpenGL standard, for example: If the new
>>     version is backwards-compatible, only the minor version number
>>     changes. If it isn't, the major version number must be incremented.
>>
> 
> 
> I prefer 1. The FSF use 2 for its GNU software and others started with it,
> too. But after a while most of them tend to increase major numbers. E.g.
> 3.0, 3.11, 95, 98, 2000

I think we should do (1).  But we should also keep the current mechanism of 
allowing a package to specify a range of dependencies, the reason being that 
even when an interface upgrade isn't fully compatible, the package might still 
work with it, and this is a property of the consuming package, not the package 
that is depended on.  (incedentally .NET has both of these facilities too, but 
only for runtime dependencies, not build-time AFAIK).

Cheers,
	Simon