[Catalog-sig] PEP 345 Update

[P.J. Eby]

At 04:50 PM 10/5/2010 -0600, Jeremy Kloth wrote:
>Here you are assuming that a file list exists for the given distribution.
>sdists, for one, do not contain this.

They will once they're being installed.


>What about tools that operate just on the metadata?  For example, determining
>what distributions to download.  It would be impossible for that to work.

So?  If nobody noticed or declared the conflict, you'll still have a 
problem once you *do* download.

Meanwhile, you can't *trust* the information in these fields to mean 
that you actually shouldn't attempt to download or install the 
package, so all you can do with the information ahead of time is 
alert the user of the *possibility* of a conflict.

IOW, merely having a "Conflicts" field will not stop you from 
sometimes downloading things that conflict with each other, nor does 
the presence of the Conflicts field actually mean you shouldn't 
download and install it anyway. (Because there might not really be 
any conflict, especially if the field gets used by people who don't 
read specifications.)