Error on Ubuntu installation around groupadd/useradd

This is from the forums...

Hello,

I am trying to install the membase binary on a ubuntu machine (64 bit) by typing:
sudo dpkg -i northscale-server_1.6.0beta4_x86_64.deb.deb


Error messages:
Unpacking northscale-server (from northscale-server_1.6.0beta4_x86_64.deb.deb) ...
groupadd: invalid option -- r

dpkg: error processing northscale-server_1.6.0beta4_x86_64.deb.deb (--install):
subprocess pre-installation script returned error exit status 1

The solution was:
You should create manually group and user befrore install binary:
groupadd northscale
useradd -g northscale -d /opt/NorthScale -s /bin/bash -c "NorthScale system user" northscale

That solved the problem.

Can we look at the code and see if we are using a possibly invalid option with 'groupadd' during the debian package installation?