package install: pinning and warnings

[tom h <uxi9000@gmail.com>]

So I've got a test box that I have sid installed on and the following in my /etc/apt/preferences

Package: *
Pin: release a=unstable
Pin-Priority: 1000
 
Package: *
Pin: release a=testing
Pin-Priority: 100

I also have these two packages installed:
sapt-listbugs apt-listchanges

I went to install libvirt and received a number of bug warnings so I was hesitant. 

Whats the best practice to get a package and NOT install the bug versions?  Raise the priority of 

the testing branch temporarily?

Thanks!