downgrading g++-4.0 using snapshot.debian.org

[John Schmidt <john.schmidt@utah.edu>]

Hi,

I have a sid chroot that I am trying to figure out which version of g++-4.0 
stopped compiling a big c++ code that I work on.  I have manually downloaded 
a couple of different versions of g++-4.0 and related packages from 
snapshot.debian.org, but it seems rather painful to just use dpkg -i *.deb.  

Is there a way to automate this process with aptitude putting in various deb 
lines in /etc/apt/sources.list?

I know that aptitude has the ability to download/install particular versions 
of the package by specifying a version after the package name.  

I haven't quite figured out how to use the power of snapshot.debian.org and 
the package manager to make short work of downgrading various packages.   Any 
pointers would be greatly appreciated.

Thanks,

John Schmidt