For some reason, on Devuan, popularity-contest submits fails with:
gpg: 4383FF7B81EEE66F: skipped: public key not found gpg: /var/log/popularity-contest.new: encryption failed: public key not found
The Debian Popularity Contest being described as an attempt to map the usage of Debian packages, I think useful that it also get stats from disgrunted Debian users forced to use a fork of the same general scope.
I do not think it data transmitted in this context is really sensitive. So the simplest hack is just to set off encryption by adding to /etc/popularity-contest.conf:
ENCRYPT="no"
# cd /scratch 