[Centos] ERROR: Could not find useradd in chroot, maybe the install failed?

[mockbuild at localhost ~]$ mock -r centos-5-x86_64-testdev.cfg init
init
clean
prep
This may take a while
ending
done
Finished initializing root
[mockbuild at localhost ~]$ mock -r centos-5-x86_64-testdev.cfg
backuppc-3.1.0-1.el5.centos.src.rpm
init
clean
prep
This may take a while
setup
build
ending
done
Results and/or logs in: /var/lib/mock/centos-5-x86_64/result