tags 977805 + security buster sid thanks There is a security angle to this FTBFS. Because ntopng is currently unable to build against ndpi 3.4, it still links against ndpi 3.0, a known vulnerable version, and users of ntopng are thus getting this vulnerable ndpi 3.0 library.
ndpi (3.4-1) unstable; urgency=medium
[...]
* New upstream version 3.4 (Closes: #972050)
- CVE-2020-11939 CVE-2020-11940 CVE-2020-15471
- CVE-2020-15472 CVE-2020-15473 CVE-2020-15474
- CVE-2020-15475 CVE-2020-15476
-Dan
