trying to apply security update

[Nik777]

Hi, I'm trying to apply a clamav security update.

I've downloaded the src.rpm, and am trying to follow the instructions.

The error I get is:

error: Failed build dependencies:
        pkgconfig is needed by clamav-0.90.3-20070531_kolab
        bc is needed by clamav-0.90.3-20070531_kolab

I presume this is a result of my not being in the correct directory, or 
(hopefully not) that information from the original build area (long 
gone) is needed to rebuild this RPM.

I've looked around on the Kolab site and can't find any reference to 
this error.

Can anyone tell me of a simple fix? I am loath to re-run the entire 
build process as I'm fairly sure that would clobber my existing 
installation.

Cheers!
Nik.