I have tried Samba 3.4.2, 3.4.1 and "latest" (which appearantly is not equal to 3.4.2) and wanted to enable the Samba 4 sources. However, doing so leads to this error message:
build/smb_build/main.pl: can't open '../lib/tevent/python.mk' at build/smb_build/config_mk.pm line 173.
The error message can be avoided by taking out one line from the samba.m4 file which refers to a file which is not there (hence the error message):
sed -i "s/SMB_INCLUDE_MK(\.\.\/lib\/tevent\/python\.mk)//g" samba4.m4
I don't think this will affect the building but I could be wrong of course.
I am sure that is not intented to happen so I'm reporting this as a bug.
Sorry, this is not a blocker. The merged build is not a supported feature yet.
4.0 will have a unified waf based build system now.