I got confused using rpl in 20.04, thanks to this page it is clarified.
What was the reason changing to a different source? Using -R option in
the original package was more reliable. SF.net version did not have
issues while the Ubuntu version did.
aa0001@test:~/projects/biospectra/cvs$ find . -n
Public bug reported:
I was getting an exception randomly on minetest master-server that I
traced back to "send_from_directory". When I searched on the web I
found the problem was already reported and resolved a few years back.
Similar Error
https://github.com/mitsuhiko/flask/issues/1169
Bug Fix