So I added the following to my rtorrent.rc,
execute = {/bin/bash,-c,mkdir -p /config/rtorrent/logs}
log.open_file = "rtorrent", /config/rtorrent/logs/rtorrent.log
log.open_file = "tracker", /config/rtorrent/logs/tracker.log
log.open_file = "storage", /config/rtorrent/logs/storage.log
# rTorrent logging verbosity for rtorrent, comment out if logs are too chatty
log.add_output = "info", "rtorrent"
log.add_output = "critical", "rtorrent"
log.add_output = "error", "rtorrent"
log.add_output = "warn", "rtorrent"
log.add_output = "notice", "rtorrent"
log.add_output = "debug", "rtorrent"
# rTorrent logging for dht and tracker traffic
log.add_output = "dht_debug", "tracker"
log.add_output = "tracker_debug", "tracker"
# rTorrent logging for storage
log.add_output = "storage_debug", "storage"
that wrote logs and told me that this line
execute = {/bin/bash,-c,mkdir -p /data/incomplete}
is causing the error. I never had a mount for /data, that line has always been there. I have no idea why all of a sudden it's been a problem. Might be cool to add those logs to supervisord.log. Anyway, I hope this helps somebody else!