ubuntu user empty passwords

For the permissions of the branches, you can add a field in vobs.config in the main category about hg_user = r10eng
On your machine, to do those same tests (with the unit test too), you should setup a r10eng also... this is described in tools_db/docs/server_setup :
create r10eng non-sudoer
$ sudo adduser r10reng

to enable r10eng without any password :
sudo vim /etc/pam.d/common-auth
change :
'nullok_secure' into 'nullok'
for ssh :
sudo vim /etc/ssh/sshd_config
change :
PermitEmptyPasswords yes
then :
sudo /etc/init.d/ssh restart
to delete the password :
sudo passwd -d r10eng