strange problem compiling source rpms

[Faheem Mitha <faheem@email.unc.edu>]

Dear People,

I recently tried to install a source rpm (as root) on a Debian
system. I got

laplace:/home/faheem# rpm -Uvh plugger-4.0-17.src.rpm
error: cannot create %sourcedir /usr/src/rpm/SOURCES

But this works on my home computer 

Chrestomanci:/home/faheem# rpm -Uvh plugger-4.0-6.src.rpm
   1:plugger
   ########################################### [100%]

Ok, so they are not exactly the same version, but very similar. Can
anyone explain what is going on? I'll been pulling my hair for a while
trying to figure out why root cannot create /usr/src/rpm/SOURCES
etc. Both laplace and my home computer Chrestomanci are supposedly
tracking sarge, and have the exact same version of rpm.

I see that I have the entire /usr/src/rpm directory hierachy installed
on my system, and I am perfectly sure I did not create it
myself. However, the rpm Debian package installation script does not
seem to install it either, so it is a mystery how it got there. Did
rpm simply create it as it needed it?

In case anyone is wondering, I am trying to install the src rpm in
order to compile it, an operation I had earlier successfully done on
my home computer.

                                               Faheem.