So the relevant output is:
0m21.1s DEBUG: Starting command: ['chroot', '/srv/piuparts.debian.org/tmp/tmp_wirspr9', '/etc/cron.weekly/update-libcifpp-data']
0m21.1s DUMP:
/etc/cron.weekly/update-libcifpp-data: 5: [: Illegal number:
0m21.1s DEBUG: Command ok: ['chroot', '/srv/piuparts.debian.org/tmp/tmp_wirspr9', '/etc/cron.weekly/update-libcifpp-data']
0m21.1s ERROR: FAIL: Cron file /etc/cron.weekly/update-libcifpp-data has output with package removed
Where can I see /etc/cron.weekly/update-libcifpp-data ? I failed to find it at
https://sources.debian.org/src/libcifpp/ :(