Good lesson for future builds - always start with previous builds throughly removed.

Thank you for your reply.

OK I made it to work:
Something from previous builds caused issue.. I removed any traces of deluge from /usr/local and it started working.

It must be related to some raspberry pi specific issue as I tried the same build on Debian Bullseye running on Intel CPU and all works: # deluged -V deluged 2.1.1 libtorrent: 2.0.7.0 Python: 3.9.2 OS: Linux 5.10.0-16-amd64 Unfortunately error I've got on RPi does not point into anything specific. Ho...

I build v2.1.1 from source but when I try to run it: # deluged -V Traceback (most recent call last): File "/usr/local/bin/deluged", line 33, in <module> sys.exit(load_entry_point('deluge==2.1.1', 'gui_scripts', 'deluged')()) File "/usr/local/bin/deluged", line 25, in importlib_lo...