Bug#351056: many packages involved, not just python-twisted

[Andrew Schulman <andrex@alumni.utexas.net>]

> You have two builds of the same package/version. Apt-get wants to
> install one of them but your cache already contains the other one. So
> every upgrade reinstalls the wrong one.

Well I don't understand that; and if it's true it seems to still be a bug.  
We still have the behavior that apt-get is trying to reinstall the same 
packages over and over again with the same versions as are currently 
installed.  Why do those package files have the same package name and 
version number, if they're really different?  But maybe that's not 
apt-get's fault; I don't know enough about it to know.

Anyway if an occasional 'apt-get clean' is all that's needed to work around 
the problem, I can live with that.  However...

> apt-get clean; apt-get upgrade

No, this does not fix the problem.  apt-get still wants to reinstall all of 
the same packages.

Thanks,
Andrew.