[gentoo-portage-dev] Can emerge be instructed not to upgrade a dependency?

[Amit Dor-Shifer]

Hi.

I want package A to incur a rebuild of package B, due to a newly 
introduced USE flag which affects B.  I wish to express this in the 
package's ebuild. I therefore DEPENDed A in B[use_flag]. When I attempt 
to emerge A, portage offers to *upgrade* the dependency, taking in the 
new USE setting (there's an available upgrade in the tree). I want the 
dependency to be *rebuilt*, maintaining the same version currently 
installed. Can I tell emerge to do that?  I'm looking for a general 
method of doing this, I.E. I wish to remain unaware of the specific 
version of the installed B package: If it's there, don't upgrade it, 
just rebuild w/new USE flag.

10x,
Amit