net-dns/knot has changed DNSSEC key database formats from 2.4 to 2.5. They bundle a Python script (pykeymgr) to change formats; see https://www.knot-dns.cz/docs/2.5/html/migration.html#kasp-db-migration However, running pykeymgr using Python 3 results in the following error: File "/usr/sbin/pykeymgr", line 512 def __call__(self, parser, namespace, values, option_string=None): ^ TabError: inconsistent use of tabs and spaces in indentation That seems to be fixed in https://gitlab.labs.nic.cz/labs/knot/commit/33919a7c7070c8ffc575b0752d0abdcae978b8bf. There is also https://gitlab.labs.nic.cz/labs/knot/commit/d0c1a9ed0fed505936115922aff7bf3bd6fd4142, described as "python3 compatibility". Both of these commits are included in net-dns/knot-2.5.2, so with any luck, a simple version bump should make pykeymgr run with Python 3. However, I have not tested that.
2.5.2 is in Portage now, and works.
Sorry for the delay, fixed in net-dns/knot-2.5.3 now in tree.