Problem installing from deb file and ignoring dependencies

[Colin Law]

I am trying to install a package A (from a .deb file) that depends on
package B, but B is not available for my platform so I have built B
from source.  I cannot install A by using
dpkg -i A.deb
as it complains about the missing dependency.  I can install it by using
dpkg -i --ignore-depends=B A.deb
but this is not a good solution as the next time I install something
it complains about the package being broken.

I have got over the problem by unpacking A.deb, removing the
dependency and repackaging but I feel this cannot be that unusual a
requirement and there must be a better way.  As it stands I will have
to repeat the exercise to install an upgrade to A.  Is there a better
way?

In case it is relevant I am installing get-iplayer (A) on a SheevaPlug
PC running Jaunty.  I can't upgrade the Sheeva as Jaunty was the last
version that supported the architecture.  get-iplayer is not in the
Jaunty repository but it is architecture independent (perl) so I can
use the deb from a the currrent ubuntu distribution.  It depends on
rtmpdump (B) which I have built from source.

Colin