FSMO role transfer issue

[Daniele Dario]

Hello everyone,
just upgraded one of my DCs from 4.8.2 to 4.8.5 and when I try to
transfer the FSMO roles back to it I get the following error:

root at kdc01:~/samba/samba-4.8.5# samba-tool fsmo transfer --
role=domaindns -U administrator
Password for [SAITEL\administrator]:
ERROR(<type 'exceptions.AttributeError'>): uncaught exception -
'module' object has no attribute 'drs_utils'
  File "/usr/local/samba/lib/python2.7/site-
packages/samba/netcmd/__init__.py", line 176, in _run
    return self.run(*args, **kwargs)
  File "/usr/local/samba/lib/python2.7/site-
packages/samba/netcmd/fsmo.py", line 520, in run
    transfer_dns_role(self.outf, sambaopts, credopts, role, samdb)
  File "/usr/local/samba/lib/python2.7/site-
packages/samba/netcmd/fsmo.py", line 129, in transfer_dns_role
    except samba.drs_utils.drsException, e:

The error is triggered only when trying to transfer domaindns and
forestdns roles and I solved it just adding 

import samba.drs_utils

directive in fsmo.py

Another issue I can signal is that when attempting to transfer all the
roles in one command (--role=all), it hangs after the first transfer.
I've tryied to add a one second sleep between the transfer_role calls
and everything works fine.

These two used to happen also in all the previous version I used so
this is not a regression.

The DC runs on an Ubuntu 16.04 x64, the samba package is built from
source with

root at kdc01:~/samba/samba-4.8.5# ./configure --disable-cups --disable-
iprint --with-systemd

root at kdc01:~/samba/samba-4.8.5# make && make install

and installed in the default location /usr/local/samba

The python packages installed on the server are

root at kdc01:~/samba/samba-4.8.5# aptitude search python | grep 'i . py'
i A python
i A python-all
i   python-all-dev
i   python-apt-common
i   python-crypto
i   python-dev
i   python-dnspython      
i   python-gpgme
i   python-m2crypto
i A python-minimal
i A python2.7
i A python2.7-dev
i A python2.7-minimal
i   python3
i   python3-apport
i   python3-apt
i   python3-chardet
i   python3-commandnotfound
i   python3-dbus
i   python3-debian
i   python3-distupgrade    
i   python3-gdbm
i   python3-gi
i   python3-minimal
i   python3-newt          
i   python3-pkg-resources
i   python3-problem-report
i   python3-pycurl
i   python3-requests
i   python3-six
i   python3-software-properties
i   python3-systemd 
i   python3-update-manager
i   python3-urllib3
i   python3.5
i   python3.5-minimal

Best regards,
Daniele.