Virtual provides for files in /var/log

[Panu Matilainen]

On 07/18/2013 04:42 PM, Lennart Poettering wrote:
> On Thu, 18.07.13 15:47, Panu Matilainen (pmatilai at laiskiainen.org) wrote:
>
>>>> I would suggest it, but it is not recommended by guidelines :( so I
>>>> suggest some (not yet) standardized virtual provide, which will be
>>>> more descriptive than "syslog-files"
>>>>
>>>> Vít
>>>>
>>>> [1] https://fedoraproject.org/wiki/Packaging:Guidelines#File_Dependencies
>>>
>>> I guess this comment doesn't apply if we explicitly add Provides:
>>> /var/log/messages to all packages that provide the file. Hmm, or maybe
>>> no, I don't grok RPM well enough...
>>
>> Well the guideline is really just a recommendation for optimizing
>> yum behavior, nothing more. But yes, an explicit "Provides:
>> /some/path" goes into the main repository metadata so resolving a
>> dependency on that path doesn't require downloading the big bad file
>> lists.
>
> Hmm, Panu, but who does this exactly work? If at least one package
> explicitly provides /some/path, and some others only implicitly provide
> it, is the big bad file list download skipped?
>
> Which would mean either *none* of the providers shall explicitly provide
> the file (which would be slow), or *all* of the provides explicitly
> provide the file? If some would explicitly provide it, and others only
> implicitly, then things would be broken?

Hmm, good question. I've no idea what yum does in that situation.
Most other depsolvers (have to) always download the full filelists 
anyway, making the point moot, but since yum tries to avoid it... My 
*guess* is that yum would go downloading the full filelists anyway when 
the path is outside the "common paths" stored in the primary metadata 
directly.

	- Panu -