Testing ports of rust software w/o building rustc

Hi,

I'm working on porting some rust software, but testing the port in my
local poudriere doesn't work, as I run out of memory systematically (no
matter how much swap I try to add to help).

Is there a way to avoid having to build rustc and yet test the port in
isolation, to be sure I've captured all the dependencies? Or is there
something I'm missing here I should be doing?

Thanks,
Nicolas.