Control: reassign -1 base-files
Control: tags -1 beowulf

I have tracked this down to the parsing of /etc/dpkg/origin/*

Reportbug expects the Bugs: entry to be a debbugs:// url and handles
it correctly. This error arises from the http{s}:// url which it doesn't
understand.

See https://git.devuan.org/devuan-packages/reportbug/blob/suites/unstable/reportbug/debbugs.py#L936

The fix is relatively trivial: change the Bugs: url to debbugs:// scheme.

Mark