I am going to create a AD DC and files server at my work on DELL PowerEdge T620 with Ubuntu 12.04LTS 64 bits. I have some errors like "samba wscript: error: Traceback (most recent call last):
Sorry to be not more precise but I remove all then try 4.1.1 and this one installed without any issue.
for information: I am going to traduce in french and improve : https://wiki.samba.org/index.php/Samba_AD_DC_HOWTO
draft is visible at : http://doc.ubuntu-fr.org/utilisateurs/bcag2/samba4
we build 4.1.2 on ubuntu 12.04 without a problem. If you can reproduce the problem and if you have the configure output so that we can see what is wrong on your system, then please reopen.