I can confirm that this is caused by /tmp beeing mounted nodev. sudo piuparts -t /home/<me>/tmp --do-not-verify-signatures --fake- essential-packages ca-certificates --testdebs-repo 'deb [ trusted=yes ] https://dl.cloudsmith.io/public/volkszaehler/volkszaehler-org-project/deb/debian bullseye main' -d bullseye /var/cache/pbuilder/result/vzlogger_0.8.8_amd64.deb
worked (in case someone needs a workaround).
