[Samba] samba-tool throws Segmentation fault since 4.6

[Johannes Engel]

Dear list,

since Samba 4.6 (holds also for 4.7) samba-tool started throwing 
segmentation faults on my systems for some operations: This includes 
e.g. domain join after filling the "questionnaire", ntacl sysvolcheck, 
drs showrepl etc. Others like testparm seem to work as they used to do.

I have filed a bug report (#12682), but no reply so far. Since I am not 
a python expert, I have no idea where to start debugging. Would you mind 
to assist?

Thanks a lot!

Best regards
Johannes