[Yum-devel] rpm --requires and primary.xml <requires>

[Panu Matilainen]

On Thu, 30 Apr 2009, Seth Vidal wrote:
>
> On Thu, 30 Apr 2009, Seth Vidal wrote:
>> 
>> We've discussed putting them in the repomd.xml so you know that "this repo" 
>> needs this set of rpm capabilities. just to avoid dumping a lot of mindless 
>> metadata here.
>> 
>> but, again, the BEST CASE is that you have to stop what the user wants to 
>> do, see if you can find an rpm update to satisfy it, run that transaction 
>> w/all of its deps, and then come back to what the user wanted to do.

And you'd have to restart yum (or manage to unload and reload the rpm 
module entirely) after such update, otherwise yum would still be using the 
older librpm.

> oh and I failed to mention one other thing.
>
> you have to find an rpm that provides that capability w/o ANY INFORMATION OF 
> THE KIND. B/c the rpm PACKAGE doesn't provide that in its provides.

Putting the rpmlib() provides into regular provides of the rpm package 
would be wrong as they're runtime dependencies, it'd need a new 
dependency flag or such that says so. Which btw would be useful 
occasionally, I remember a couple of cases where something like this 
would've been needed.

> So the best we can do is abort and tell the user they can't do anything.
>
> great.

Well, that's what rpm will tell the user eventually anyway, after 
a potentially huge download. I don't see how that's better for the user 
than having yum say so before wasting time on downloading stuff that 
can't be installed.

 	- Panu -