You could also stomp around in Proc::Background's namespace. Generally a bad idea, but it can be useful in cases like this. 
use Proc::Background; # Make sure it's loaded at compile-time
package Proc::Background;
no warnings 'redefine';
sub new { do_stubby_stuff(@_) }

package main;
# Go about your testing business

[download]
This will replace Proc::Background::new with your own version, which can do whatever works best for your tests. Note, though, that this doesn't allow for using SUPER to access the original version of the replaced sub(s) because it's redefining the existing sub, not overriding them in proper OO fashion.

In reply to Re: Overriding a module that is used by a program I'm testing by dsheroh
in thread Overriding a module that is used by a program I'm testing by Narveson

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